YoungPetro - 19th Issue - Autumn 2016

AUTUMN / 2016 ISSUE #19

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Dear readers, As the years are passing by we get that chance to share with you most outstanding papers written by the people from all over the world. YoungPetro is a student magazine, our readers are mostly students and autumn is the most fruitful and inspiring season of the academic year. We have new energy, strength and ideas to begin another chapter on our educational path.

Speaking about the passage of time I would like to mention that the Faculty of Drilling, Oil & Gas at AGH UST in Krakow, which is the homeland of our magazine, will be celebrating its 50th anniversary this year! Since it was established in 1967 it broadly co-operates with scientific centers in Poland and abroad. Congratulations!

In this issue we have a pleasure to present to you articles written by students from Malaysia, India and Poland in a wide range of topics. From general ones – Milan Zięba, Poland on LNG technology to those very advanced- for example by Natalie Chu Mei Fung, Malaysia on Wellbore cleaning by nanoemulsion. Traditionally you can also read about current affairs in On stream and learn some interesting facts from How it works. We hope this variety will be an inspiration for your own work and ideas!

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Editor-in-Chief Natalia Krygier n.krygier@youngpetro.org Deputy Editor-in-Chief Patryk Bijak p.bijak@youngpetro.org Art Director Alicja Pietrzyk alicjaa.pietrzyk@gmail.com Editors Wojciech Kurowski Jakub Pitera Monika Saczyńska Graphic designer Patrycja Lanc

Ambassadors Josiah Wong Siew Kai - Malaysia Alexander Scherff – Germany Viorica Sîrghii - Romania Athansios Pitatzis – Greece Sagar Karla- India Alex Zakrzewski- UK Muhammad Bilal Akram- Pakistan Serhii Kryvenko- Ukraine/ Texas, USA Alahdal A. Hussein- Malaysia Ivan Bošnjak- Croatia Publisher Fundacja Wiertnictwo - Nafta - Gaz, Nauka i Tradycje Al. Adama Mickiewicza 30/A4 30 - 059 Kraków, Poland www.nafta.agh.edu.pl

Proof-reader Adam Sikorski

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Marketing Filip Czerniawski Maksymilian Łękowski Karolina Zahuta

2300-1259

Published by

An Official Publication of

The Society of Petroleum Engineers Student Chapter P o l a n d • www.spe.net.pl

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On Stream – Latest News 7 Patryk Bijak

Few More Words About 8 LNG Technology Milan Zięba

Cold Heavy Oil Production 10 With Sand –(CHOPS) Kon Aguek Deng

Wellbore Cleaning By Nanoemulsion 15 Natalie Chu Mei Fung, Ph.D. Wan Rosli Wan Sulaiman

Polish Shale Gas “Eldorado” 18 Jakub Frankiewicz

How It Works? 23 Wojciech Kurowski

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Are you a student?

Are you interested in Oil&Gas Industry?

Do you want to present yourself in front of the biggest companies from the Industry?

Join the “East meets West” Congress on 4-7th April 2017 in Krakow, Poland!

Just register at: platform.emwcongress.org

During this edition we will as well host Petrobowl and SPE Student Paper Contest!

For more info visit emwcongress.org

Patryk Bijak

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On Stream – Latest News Patryk Bijak

The Niger Delta Oil Wars Are Unlikely To End Soon The Nigerian government took steps to reduce the level of violence in the Niger Delta and enable oil production to return to pre-conflict levels and announced in August that it had resumed amnesty payments to former militants in the Niger Delta.

About 30,000 former fighters are now receiving amnesty payments of $206 per month, on the condition that they end their attacks on pipelines in the Niger Delta. However, it remains uncertain whether this will lead to a real decrease in violence in the Niger Delta and unlikely that the reintroduction of amnesty payments will change the dynamics of the conflict in the Delta. The main difficulty with attempts to end conflict in the Delta through the resumption of government program is that many of them never received amnesty payments in the first place and were excluded from the PAP Clean Energy Using CO2, is it possible?

Scientists have discovered a way to turn carbon dioxide into ethanol with a single catalyst. The discovery, may have huge implications on balancing the power grid supplied by intermittent renewable sources, by creating a way to store excess electricity generated from wind and solar. The carbon dioxide-to-ethanol reaction uses low-cost materials, and can be conducted at room temperature – and more

importantly, the researchers believe it could be scaled up to industrial-level applications. Scientists at the Department of Energy’s Oak Ridge National Laboratory made the random discovery back in 2014, and published their study in september, after having tested the reaction multiple times at their lab.

Shell Disposes of Gas Properties in Canada for $1 Billion In the fourth quarter of 2016 Royal Dutch Shell, through its affiliate Shell Canada Energy, is going to sell approximately 206,000 net acres of gas and non-core oil properties in Western Canada. The buyer is Tourmaline Oil Corporation. Transaction is estimated to be $1.037 bilion. The assets are a combination of developed and undeveloped lands, along with related infrastructure, producing 24,850 barrels of oil equivalent per day of dryg as and liquids. 

“Shell retains a significant shale position in Canada and we are actively working to mature our attractive core asset base in the Montney and Duvernay,” said Andy Brown, Shell’s upstream director.

“At the same time we are strengthening our shales business and creating shareholder value by selling assets that do not fit our near-term development plans,” he added.

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¡¡

Few More Words About LNG Technology

Few More Words About LNG Technology Milan Zięba

**AGH University of Science and Technology ÞÞPoland milanzieba@gmail.com  University  Country  E-mail

LNG stands for Liquefied Natural Gas and it is odorless, colorless, non-toxic and non-corrosive gas, which contains mainly methane. The components such as nitrogen, higher aliphatic hydrocarbons and other trace substances amount to about 5%. This fuel is safe and ecologically-friendly. It is beyond any comparison with crude oil or liquefied petroleum gas (LPG). LNG is playing more and more important role in global energetic market but are we aware that the increasing demand for natural gas and the limits of throughput of pipelines result in the increase of the number of LNG terminals. Do we really know how the journey from gas fields to engines looks? Do we know technologies of liquefying and re-gasification?

Gas extraction

Purifying and liquefying

Some natural gas resources are in remote locations.

Transporting gas on long distances by pipeline can be expensive and impractical. The solution is to liquefy gas by cooling it, which shrinks its volume for an easier, more economical and safer transportation by methane carriers. The journey of LNG begins in the gas fields in Qatar, Algeria, Indonesia, Australia or Nigeria. Natural gas extracted from the ground contains impurities, water and other associated liquids. First, it is processed to be cleaned. After purifying, natural gas can be safely liquefied. This process is carried out in heat exchangers. During the cooling process, the gas volume is reduced by almost 600 times. Clear, colorless, non-toxic liquefied natural gas-LNG is received, which is much easier to store and transport. The LNG is kept in insulated tanks until it is ready for loading into a carrier. The transport ends up in huge terminals in Asia and Europe. When the ship arrives at its destination, the LNG is transferred to a re-gasification plant, where it is heated, turning it back to its gaseous state. The gas is then transported via pipelines to customers, providing energy for homes and industry.

Transport

Re-gasification

Delivery

Graph 1. Scheme of LNG journey

Purifying process To purify the natural gas, it is passed through a series of pipes and vessels where gravity helps separate gas from some of the heavier liquids. Other impurities are then stripped out. The natural gas passes through a water based solvent that absorbs carbon dioxide and hydrogen sulphide. These

would otherwise freeze when the gas is cooled and so cause blockages. Next, any remaining water is removed, as this would also freeze. Finally, the remaining lighter natural gas liquids (mostly propane and butane) are extracted to be sold separately or used as refrigerant later in the cooling process. The traces of mercury are also filtered out.

Milan Zieba Patryk Bijak

Liquefying process Liquefying process is carried out in heat exchangers. These are devices which allow the heat from a fluid (a liquid or a gas) to pass to a second fluid. The fluids are not mixed and do not come into direct contact. A coolant, chilled by giant refrigerator, absorbs the heat from the natural gas. It cools the gas to –162°C, shrinking its volume by 600 times, making it turn into a clear, colorless, non-toxic liquefied natural gas, LNG. Re-gasification process.

The process is based on returning the gas from the liquefied state to its gas state by heating. It can be performed in LNG terminals as well as distribution stations, appropriately equipped ships or receivers’ plants. The most essential devices for that operation are vaporizers of different capacity, construction and method of heating.

Liquefied natural gas vaporizers may be divi­‑ ded into: • vaporizers heating up to a temperature equivalent

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to the ambient temperature: – vaporizers heated by sea or river water (ORV) – vaporizers heated by air (SPV) • vaporizers, with direct heating, heating up to a temperature higher than the ambient temperature: – fire heating-gas burners – electric heating • vaporizers with direct heating with the use of heat carrier medium: – steam water heaters – water heaters heated by immersed gas burners – isopentane heaters or other energy carriers.

Conclusion Extraction, liquefaction, transport and re-gasification of liquefied natural gas is a long and complicated process involving the use of state-of-the-art technology. The global energy demand is constantly growing. To satisfy this demand, gas and the technology of its processing are going to form an increasingly important role within the up-coming years. 

References: [1] http://www.polskielng.pl [2] http://lng.edu.pl [3]http://www.shell.com/energy-and-innovation/natural-gas/liquefied-natural-gas-lng.html [4]http://www.explainthatstuff.com/how-heat-exchangers-work.html

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Cold Heavy Oil Production With Sand – (CHOPS)

 Cold Heavy Oil Production With Sand – (CHOPS) Kon Aguek Deng **University of Petroleum and Energy Studies ÞÞDehradun, India kon.deng49@gmail.com  University  Country  E-mail

Albeit the unconventional resources involve many problems in exploration and production; these are gaining huge momentum since the huge demands of oil and gas are not gratified by the conventional sources. Heavy crude oil, being one of the unconventional sources, is the oil that is highly viscous, and cannot flow to production wells under normal reservoir conditions.

Many techniques are used for extracting heavy oil with Cold heavy oil production with sand (CHOPS) being one of them. CHOPS is a technique for extracting difficult heavy crude oil (having API gravity <20) where sand is used as a means for enhancing the productivity of the oil well. CHOPS was developed in the 20th century when it was discovered by small local operators who performed better at sand producing wells and it was promoted since it was economically compared to other methods. This method is being successfully used in vertical or deviated wells in few parts of the world.

Introduction With the conventional oil resources declining, more and more effort is being put up in the unconventional resources sector to fulfil the rising demands. The conventional oil already reached its peak last decade, though it still has not declined completely. All the serves providing companies and researchers are working on development of

new methods and tools to enhance oil recovery, which involve tar sand, shale gas, cold bed methane, heavy oil makes a big difference in the peak oil and extending it longer. In this paper we study the significance of Cold Heavy Oil Production with sand (CHOPS).

Heavy oil is a crude oil with API gravity of 10 to 20 and a viscosity of 100–1000 centipoises and a specific gravity of 0.92. More than two-third of the world’s total oil reserve are heavy and bitumen.

There are a numerous methods which are used to increase the productivity of the heavy oil reservoirs.

Some of them are VAPEX (Vapor Assisted Petroleum Extraction), SAGD (Steam Assisted Gravity Drainage), THAI (Toe to Heel Air Injection) and CHOPS (Cold Heavy Oil Production with Sand).

VAPEX is a non-thermal recovery method that involves injecting vaporized solvents into heavy oil, creating a vapour chamber for oil to flow. SAGD is a thermal in situ recovery method that involves drilling two horizontal wells, one above the other through which steam is continuously injected softening bitumen so that it drains into the lower wellbore and is pumped to the surface. THAI involves in-situ combustion but with horizontal wells so that the combustion products and heated hydrocarbons flow almost immediately downward into the horizontal production well. CHOPS involve the deliberate initiation of sand influx during the completion procedure increasing the permeability of the reservoir, allowing heavy oil to flow.

CHOPS and Thermal EOR Methods By comparing the thermal recovery methods and cold heavy oil production with sand (CHOPS) process, it turns out that it is non-thermal recovery method that produces oil and sand simultaneously.

   



Progressive cavity pumps (PCPs). It’s a type of pump which is used to pump both oil and sand simultaneously.

Considerable amount of sand is produced with oil.

Patryk Bijak 11 Kon Aguek Deng Formation of wormholes is one of the important factors for high production rate.

Foamy oil solution gas drive, (foamy oil pressure).

The formation of a wormhole network happens during the high production of sand. During • With the help of of natural energy the reservoirformation ta and Saskatchewan, Canada.

The around production of bay the production a zone of inincreasing permeability, if formed the or the formation which decreases the recovery cost CHOPS in Alberta accounted for nearly 20% of the zone of the producing well, in addition to wormhole network, gas bubble phase is also (improve profit). total Canada heavy oil primary production in 2000. generated.

• Progressive cavity pumps (PCPs). It’s a type of pump which is used to pump both oil and sand simultaneously.

• Considerable amount of sand is produced with oil.

• Formation of wormholes is one of the important factors for high production rate.

• Foamy oil solution gas drive, (foamy oil pressure).

• The formation of a wormhole network happens during the high production of sand. During the production of a zone of increasing formation permeability, if formed around the bay zone of the producing well, in addition to wormhole network, gas bubble phase is also generated.

The two mechanisms are referred to as “wormhole network growth” and “foamy oil flow” respectively.

They are responsible for the production success of CHOPS. The CHOPS technology started in the USA, California, prior to the First World War. Now, the application of CHOPS is mostly in the Lloydminster, Lindberg and Cold Lake areas in Alber-

Mechanisms involved in flow: These are basically the reasons which are responsible for the amplification in fluid flow in this method: 1. The fluid mobility increases due to sand influx as the Darcy velocity increases. This increase is due to the fact that a mobile medium leads to the increase in the fluid velocity (vf) as then differential velocity (vd) is calculated. In the case of an immobile medium, the Darcy velocity is calculated with respect to a fixed frame of reference and hence is comparatively lower.

Vd = Vf – Vm (in the case of a mobile medium)

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Cold Heavy Oil Production With Sand – (CHOPS)

This effect is valid only until there is huge sand influx in the early stages. With time as sand influx decreases, the importance of this effect diminishes.

2. As sand comes out of the well, there is a formation of a magnified zone of permeability. The space created is in the form of channels (wormhole), which are either empty or contain a slurry of sand, oil, water and gas.

3. As the well pressure decreases, exsolution of the gases present in the oil takes place. This leads to formation of bubbles and hence foamy oil is developed in the well. These bubbles form an internal force for the fluids to flow. Since these bubbles do not coalesce there is no process by which gas pressures decrease. Hence, there is maintenance of GOR value.

4. There is a number of reasons which lead to the blockage of the pores in a well causing its impairment. Firstly, heavy oil consists of asphaltenes, semi- solid materials which tend to aggregate in low pressures causing pore blockage. Secondly, the fine grained sediment in the reservoir rocks may move due to viscous force drag or due to high pressure gradient again leading to the blockage of pore throats. Lastly, the formation waters containing mineral species may also precipitate at the pores. However, in this method, due to the continuous movement of sand, these blockages are eliminated and hence,

there is less likely chance of well impairment leading to continuous productivity.

The production variations in a CHOPS well with time: • Initially, sand production rate is high enhancing the oil production rates.

• With time (several months) the sand influx rates decline and the oil production increases tremendously.

• These oil production rates decline as reservoir impairments begin to govern. Throughout this time, the GOR values remain consistent (quintessential of a conventional oil well).

• During the later stages when large amounts of sand has been produced, gas cap begin to develop in the well bore increasing the GOR values.

• Now, due to higher permeability and long channels, the water influx becomes prominent.

• Sometimes sudden halt of sand production leads to no oil production, indicating the perforation blockage or sand compaction in the well bore, which requires workover process.

CHOPS in India India has a huge amount of tar sand, which if produced, will increase Indian economy and India will not have to import oil from other countries. Furthermore, the conventional oil is at its peak and the

The production variations in a CHOPS well with time:



During the later stages when large amounts of sand has been produced, gas cap begin to develop in the well bore increasing the GOR values.  Now, due to higher permeability and long channels, the water influx becomes prominent.

Patryk Bijak 13 Kon Aguek Deng  Sometimes sudden halt of sand production leads to no oil production, indicating the perforation blockage or sand compaction in the well bore, which requires workover process.

production is declining. With time the tar sand will help extending the oil peak, with some major heavy oil discoveries in India. We need to give importance to this resource and implement recovery methods with good productivity rates for exploiting it.

and also is an economical method as it does not require expensive tools and chemicals to enhance the production rates. Hence, it can be used and applied in heavy oil reserves so that oil resources in India are amplified meeting the demand

There have been several discoveries of tar sand in India with the major discoveries being in Rajasthan.

The discoveries are:

Conclusion

• 130 million tonnes of heavy oil deposits at Boghawala sandy desert area in Rajasthan’s Barmer

by OIL [1].

• North Kadi field of western offshore basin by ONGC [2].

• Heavy oil reserves in an oil well in the Nachna area, Jaisalmer by OIL [3].

Why should CHOPS be used in India CHOPS is a primary method of production with high rates. In-situ thermal combustion and other methods of oil enhancement recovery have not been successful in Indian wells due to the lack of technology creating the need for primary methods.

Moreover, CHOPS does not require much technological advancements in which India lacks till date

CHOPS is a simple yet effective way of producing heavy oil with higher recovery.

This method, despite of success and low economic costs, has not been adopted permanently in many areas.

• It is due to the fear that the sand may block the bores, which actually does not happen. Contrarily, it leads to cleaning of the blocked pores.

• Also, the lack of technology in the refining industry for upgrading heavy oil is also a barrier hindering its success. Though with time, as technology is improving, it will slowly diminish.

• Another reason for its denial is the huge amounts of sand produced. These sands were earlier used for laying roads but with roads becoming thicker it is not recommended by the government. A solution to this problem is the pumping of sand with the heavy oil into the salt caverns below the reservoir

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Cold Heavy Oil Production With Sand – (CHOPS)

known as the Super sump. With natural settling, the oil comes to the top and is then extracted leaving sand behind in the caverns.

• These problems are now negligible due to advancement in ideas and technology with time. Hence, it can be used even in the wells which have been

shut down (at low economic rates as compared to that required for new wells).

• To satisfy the increasing world demands of oil, this method can be one of means to this objective and being an easy and expensive one could be economical with today’s oil rates. 

References [1] Training : Industry training and Learning Resources. (n.d.). Retrieved August 2014, from Rigzone: https:// www.rigzone.com/training/heavyoil/insight.asp?i_id=195 .

[2] Dusseault, D. M. (2002). Cold Heavy Oil Production with Sand in the Canadian Heavy Oil Industry.

Alberts: Government of Alberta.

[3] Brigida Meza-Diaz, R. S. (2013, December). Sand on Demand: A Laboratory Investigation on Improving Productivity in Horiontal Wells Under Heavy-Oil Primary Production - Part - II. SPE Journal .

[4] Foster, F. L. (n.d.). CHOPS Without Sand: Will the SuperSump Revolutionize Oil Production? Heavy Oil Science Center .

[5] Petrowiki Page http://petrowiki.org/PEH%3ACold_Heavy-Oil_Production_With_Sand.

PatrykChu Bijak Natalie Mei Fung, Ph.D. Wan Rosli Wan Sulaiman

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 Wellbore Cleaning By Nanoemulsion Natalie Chu Mei Fung, Wan Rosli Wan Sulaiman, Pd.D. Introduction **University of Petroleum and Energy Studies ÞÞMalaysia natalie12@spe.petroleum.utm.my  University  Country  E-mail

The problems in pipe sticking originated by inadequate wellbore cleaning have long been an issue upon the drilling operation in oil and gas industries. Conventionally, surfactant clean-up systems were used in the industry to clean up the wellbore. This system required turbulent flow and large volume to solubilize residue efficiently. An alienated surfactant system would cause emulsion blockage. Subsequently, this blockage would lead to a reduction in oil production. This paper proposes a new wellbore cleaning technology by using nanoemulsion.

Nanoemulsion is a clear, thermodynamically stable and ultra-low interfacial tension solution which can effectively reduce oil-water interfacial tension (IFT) down to <0.001 mN/m, solubilising much larger amount of oily hydrocarbons without any mechanical stirring needed. The comparison of mud removal efficiency between the existence wellbore cleaning agent and nanoemulsion is done in this study through laboratory scale set-up at ambient and HPHT conditions. A study found that nanoemulsion is the most effective way in removing oil-based mud in all study conditions at tested duration of <5 minutes. The cleaning mechanism proposed are: instantaneously reduction of interfacial tension between oil-water and oil-solid surfaces, emulsification and solubilisation of oil content, facilitation of wettability and allowing water molecules to penetrate in-between oil and solids surfaces, causing the oil to spontaneously repel from the hydrophilic solid surfaces, and separation of oil from water and solids.

The revenue of oil and gas industries is projected upon the efficiency in drilling operation. An inefficient drilling operation will ultimately result in cumulative financial losses. In Malaysia, the major limiting factor for a successful drilling operation is if it is identified as relying profoundly on adequate wellbore cleaning upon the commencement of pipe sticking. This operation is intensely significant in high deviated well through the soft and unconsolidated formation. As drilling progresses, mudcake is thickened and attached to the heavy casing and cement wall. It would result in a tight hole condition.

Hence, poor log quality and pie sticking happens.

Consequently, it can induce a drastic decline in the rate of oil production and stability of wellbore on hold. Thus, wellbore cleaning is being initiated.

In wellbore cleaning, drilling fluid is applied to lubricate the drill string, keep the bit cool, provide hydraulic power to the drill pit and maintain the stability of the bored hole. Conventional surfactants require large volumes and turbulent flow to effectively remove the residue. Unsuitable surfactants may create emulsions with the drilled mud and lead to the contamination of brine upon completion. The emulsion leads to a further decline in oil production. To the disadvantage of oil and gas industries, it’s a time consuming process. In every industry, time means money.

Nanoemulsion technology offer the best solution for the above-mentioned issue. Nanoemulsion is a clear, thermodynamically stable and ultra-low interfacial tension solution. Typically, the size of nanoemulsion ranges between 1–100nm, the interfacial tension between the aqueous and hydrocarbon phase in nanoemulsion system can be as low as 0.0001mN/m, compared with ordinary emulsion or macroemulsion (20–50mN/m). Nanoemul-

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sion is actively solubilizeable in both water and oil without any agitation or turbulent flow. After the nanoemulsion is injected into the reservoir, the emulsion droplets will capture on the surface of mud residue. When the temperature increases or contact with water formation is established, then the antiscaling ingredients will release from the emulsion slowly, which can prolong the span of the useful effect of antiscaling agent. The colloidal particles in nanoemulsion are able to quickly and effectively reach the target layer because their sizes are smaller than rock pore throats and it poses a good capability of penetration rate. Nanoemulsion is able to keep stable for a long time and dissolve or disperse big liquid droplets and organic impurities, which may regain the rock permeability.

Methodology The experimented started by formulating an oilbased mud in an ambient condition of a HPHT Chamber at 250°F for 30 minutes. After that, the mud was poured out from the HPHT chamber to test the rheology properties of the oil-based mud. The mud removal tests were run by coating

Tab. 1 Result of Mud Removal Efficiency Test

Wellbore Cleaning By Nanoemulsion

rheometer cell with oil-based mud residue. The rheometer cell been immersed into the cleaning agents (nanoemulsion and surfactants) separately.

Result And Discussion The results show that nanoemulsion effectively removes the mud and the mud removal efficiency (MRE) reached 100% within 5 minutes. On the other hand, the surfactant seems to have difficulty in removing the mud after 60 minutes of the application. This indicates that the current detergent-based cleaning technology is much less effective in removing the mud residues compared with nanoemulsion.

In summary, nanoemulsion has higher cleaning efficiency and can achieve the maximum cleaning efficiency faster than a surfactant. Nanoemulsion has many nucleus sites for hydrocarbon to partition within the micellar structures. These nucleus sites are surrounded by the psedo-micellar membranes, which are permeable to the oily mud residues.

These nucleus site will partition and absorb on the

Natalie Chu Mei Fung, Ph.D. Wan Rosli Wan Sulaiman Patryk Bijak

oily residue surface and nanoemulsion can reduce its IFT to as low as 0.001 mN/m. Once the nanoemulsion reaches the minimum IFT, the oily residue will migrate through the nanoemulsion pseudo-membrane into the nanoemulsion phase, which resembles physiochemical similarity to the oily residue. The oil residue will continue to partition into the nanoemulsion phase until it reaches the thermodynamic equilibrium. At this point, the nanoemulsion will separate out into two distinct phases, the oil phase and the aqueous phase, which can be easily removed by conventional separation technology.

In general, superior cleaning efficiency of nanoemulsion can be explained by its ultralow oil-water interfacial tension. Surfactant is generally unable to clean oily residue from the surface due to constraint in an insufficient reduction in oily residue of around 20–50 mN/m. The reduction of oily residue surface curvature is not as high as in nanoemulsion.

According to Rosen, oily mud residue will can only be removed by large amount and turbulence flow of surfactant. In this condition, a surfactant molecule tends to self-coagulate and form a micellar structure. The oily residue is removed by the surfactant’s micellar structure not the surfactant molecule itself.

Prieto (1996) stated that, in order to remove the oily residue, the bath and liquid soil substrate must reach the perfect contact angle (less than 90°). After reaching the perfect angle, the surfactant uses the “Roll up and Roll back” mechanism to remove the oily mud residue from the surface. This can be done with the support of a mechanical shear. Without

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stirring the solution, the oily mud residue seems to be very hard to be removed from surface.

Fig. 1 Mud Removal Efficiency of Nanoemulsion and Surfactants

Conclusion Based on the test results from the experiment, several conclusions can be drawn: 1. The mud removal efficiency of nanoemulsion is higher than of surfactant. The mud removal efficiency reached 100% within 5 minutes, while surfactant only reached 60.7% within 1 hour.

2. Nanoemulsion can remove separately the oily and aqueous phase into two distinct phases without mechanical shear.

3. Nanoemulsion offer a promising technology for removing oily mud residue in wellbore cleaning process (mud removal efficiency of nanoemulsion archived 100% in this study). 

References [1] Rosen, M. (2004). Surfactants and Interfacial Phenomena.

[2] James Curtis, L. K. (2003). Improving Wellbore and Formation Cleaning Efficiencies with Environmental Solvents and Pickling Solutions. SPE 81138.

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Polish Shale Gas “Eldorado”

 Polish Shale Gas "Eldorado" Jakub Frankiewicz a specific standpoint. Poland attempted to take advantage of the American experiences, aiming at repeating shale success at home. Croatia, after years of stagnation, wants to resume exploitation of the Adriatic oil and gas reservoirs. Each country has chosen a different path to success, but will either of them reach their goals?

**AGH University of Science and Technology ÞÞPoland jtfrankiewicz@gmail.com  University  Country  E-mail

Nowadays states are searching for individual sources of oil and gas in order to constantly improve their national energy security and become independent of price fluctuations on the world market, armed conflicts or political instabilities. Countries located in close vicinity to Russia, especially in Eastern Europe or significantly dependent on Russian gas, do it with particularly strong determination. The paper outlines steps taken in this respect by Poland and Croatia. Each of the two countries has

2008

2009

2010

2011

2012

2013

2014

4.1

4.1

4.1

4.3

4.3

4.2

4.2

14.9

14.4

15.5

15.7

16.6

16.6

16.3

Production Consumption

The oil and gas industry in Poland has a longstanding tradition. The kerosene lamp was invented by a Polish pharmacist and entrepreneur Ignacy Łukasiewicz, in 1853 – the date now considered as a symbolic beginning of the local oil and gas industry. Following the breakthrough invention, many oil rigs, refineries and pipelines were constructed in southern Poland and great many people came to try their hands at the industry. One century later, with oil and gas production reduced significantly, Poland is compelled to import gas from several countries.

Trade movements

2012

2014

Russia Federation

9.08

9.0

8.9

Other countries

1.07

2.0

1.7

Tab. 1 Structure of gas production and consumption in Poland in 2008–2014 [mln m3], BP Statistical Review of World Energy, June 2015 Tab. 2 Structure of gas pipeline import in Poland [mln m3], BP Statistical Review of World Energy 2012 and 2015

Patryk Bijak Jakub Frankiewicz

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As stated in Tab. 1 and Tab. 2, Russia remains the main origin of Polish gas imports. With the ‘Nord Stream’ pipeline now open, Poland is considerably more depended on Russia than before. Without diversification of providers and considering that no other single gas provider is capable of satisfying the high local demand, Russia, mainly Gazprom, can now effectively dictate prices. A special LNG harbour terminal is currently under construction, but it will only be opened at the end of 2015. The investment can reduce Polish dependency on Russian gas. However, it will not eliminate it.[1] In 2009, several U.S. consulting companies drafted a prognosis for Polish shale gas reserves capacity, ranging from 1.4 bln m3 [2] to 3 bln m3 (total GIP) [3]. In contrast, the U.S. Geological Survey estimated the reserves capacity at 38 mld m3 (total GIP) [4] and the Polish Geological Survey at approximately 346–768 mld m3(total GIP) [5]. In comparison, the documented resources of gas stood at 140 mld m3 at the moment [6]. It was a great opportunity for Poland to become a self-sufficient country, a new promised land, yet something went amiss and today shale gas is solely a dim recollection. What has turned it into a busted flash?

Pic. 1 Gas resource assessment concept, Shale Gas as seen, Polish Geological Survey, Warsaw 2013

Pic. 2 Area of potential existence of shale gas and oil, Shale Gas as seen, Polish Geological Survey, Warsaw 2013

A quick overview of location and geology Shale rocks, which were hoped to give Poland independence in terms of gas imports, were formed in Ordovican and Silurian seas, about 450 million years ago. [7] As shown in Picture 2, the rocks spread from the north of Poland, through its central part, all the way to the Ukrainian and Belarusian border. Three main areas of shale occurrence can be detailed, i.e.: Baltic Basin, Podlasie Depression and Lublin Basin. These reservoirs are divided into oil, gas and oil & gas prospects. Onshore drilling was set up but offshore is still considered as economically infeasible.

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High hopes and cold reality Over the last decade, due to positive prognoses from the USA and Canada, Polish shale began to attract attention. The old core samples, no more than 40, obtained mainly in 1960s and 1970s, proved useful again. Several geologists re-analysed the samples, paying special attention to such properties as TOC, thermal maturity and rock composition, for better understanding of the Lower Paleozoic Reservoir. Despite the conducted research, the commercial potential and the quality of the reservoir remained unknown as most old wells were vertical and basically no fracturing had been conducted.

Simultaneously, first licenses for prospecting and exploration were sold and geophysical seismic surveys were launched, including very costly, yet particularly helpful 3D surveys. The results were instrumental in updating the geological maps and establishing the best locations for exploration wells.

The first well was drilled in the Pomerania region.

Subsequently, exploration activities slowly moved towards the east [8].

In 2009, the newly introduced Polish energy policy indicated an increased demand for natural gas by 2030 [9]. In fact, the policy preceded the first press information of possible shale gas reservoirs in Poland. The news hinting at the possibility of extracting billions of cubic meters of gas from Polish shale rock electrified the public opinion, offering the government an opportunity to reduce dependence on Russian gas.

The initial drillings provided new data. They clarified that several individual thermal maturity zones occur throughout the country, starting with immature, through oil and liquid windows to dry gas windows or even over-mature zones. What is more, they confirmed the presence of oil or gas in nearly every well, yet the potential flow remained unknown.

However, in 2011, with many uncertainties related to the dated geological data and lack of key information about the reservoir, twelve wells were drilled

Polish Shale Gas “Eldorado”

and hydraulic fracturing was prosecuted on seven of them. After fracturing a well in Pomerania, the first stable flow of shale gas occurred in Poland. The flow tests did not appear promising as the obtained flow of 20,000 m3 per day is not enough to establish commercially viable production. A report of impact of hydraulic fracturing on groundwater and environment was drafted based on the ‘Łebień LE-2H’ well’s example [10]. The report showed no negative impact on the environment. Nevertheless, environmentalists still protested against fracturing and possible contamination of ground water resources in Poland[11].

The following year, 24 wells were drilled across the whole country [12]. Despite high activity, first hints at dropping the granted concessions were made. Companies justified their withdrawal with unclear legal regulations, bureaucracy and a failure to obtain a satisfactory flow of gas. ExxonMobil was the first major company to leave Poland. What is more, as early as March that year, the Polish Geological Survey (PGS) estimated the reservoir capacity at 346 to 768 mld m3of gas [13]. However, PGS stressed that a fair assessment of industrial resources could be made only after 100 wells had been completed. By 2015, merely 67 were drilled and only 29 fractured.

Over the following two years, 29 wells were drilled.

Despite a relatively large number of wells, there could be heard ever more voices concerning the difficult geology of the country, the impossibility of obtaining the adequate gas flow and the recession in the oil industry being just around the corner.

Foreign companies, looking for savings, began slashing costs and dropping the not fully tested and researched concessions on Polish shale. Companies such as Marathon Oil, Lane Energy Exploration and Talisman Energy withdrew from the Polish market [14]. In the meantime, a report criticising a number of Polish ministries for irregularities at issuing new regulations was published. The report stressed that without new regulations in place the access to concessions could be severely hampered for a number of companies, which, in the long term, could significantly delay resource prognoses.

Patryk Bijak Jakub Frankiewicz

In 2015, only nine companies remained, holding together 40 concessions [15]. They continue their search for reservoirs with a potential of obtaining economical flow. Until August 2015, a total of 71 wells were drilled, almost enough to conduct a thorough investigation [16]. The politicians’ promises about wide-ranging gas production in place

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by 2014 proved hollow. In fact, should companies manage to run pilot gas extractions this or next year, it would be considered a major success. Finally, new legal regulations will come into force in 2016.

Better late than never. Yet, in this case, ‘late’ shatters Poland’s hopes for becoming independent from the Russian gas.

Numbers of vertical wells

Numbers of directional wells

Total

Fracturing

13

12

25

Diagnostic Fracture Injection Test

4

0

4

Lack of fracturing

38

4

42

Total

54

16

71

Type of well treatment

Tab. 3 Summary of completed exploratory wells for shale gas 02.11.2015, Polish Geological Survey, Warsaw 2015

Reasons behind the fiasco First of all, bureaucracy and frequently changing regulations are the main reasons why Poland lost its chance at becoming independent in terms of gas imports. Reservoirs have not been documented accurately so far. Additionally, the government, after a heated debate, eventually introduced high taxes on minerals, offering nothing in return. The public campaign, or rather, the lack of it, was yet another problem. Popular myths and half-truths have not been demystified by either the government or the companies interested in drilling. Simultaneously, environmentalists continued heralding groundwater pollution, achieving truly spectacular successes in their campaign.

The politicians are the ones who caused most damage to the Polish shale project. They evoked optimistic public sentiments and failed to address the concerns of the environmentalists. The shale gas became a political weapon in the 2011 parliamentary elections campaign. In the autumn of 2011, the Polish Prime Minister said: [one can say] with

moderate optimism [that] commercial exploitation of shale gas will begin in 2014 [17].

The Polish licensing system proved to be another mistake. It resulted in the acquisition of entitlements by companies that were unable to carry on business independently and required partners to embark on shale gas exploration projects. At the same time, the state was in no position to verify the selection of business partners by companies already holding concessions.

However, the most important factor that caused the retreat of so many companies were the difficult geological conditions and the lack of appropriate technology. Conditions such as temperature, pressure or depth of shale rocks in Poland are significantly less favourable than in America. In addition, Poland has a specific clay material which clogs very quickly during hydraulic fracturing causing microcracks.

Americans spent over 20 years developing their technology, Poland wanted immediate results. It did not work [18]. A lot of time and considerable financial and legal resources have to be invested to

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render drilling more profitable in the future. Without investment, the project remains a mere dream.

The final factor contributing to the failure of the Polish shale gas revolution is the oil industry’s downturn. Companies radically reduce employment costs and count every single penny. If prices on the oil and gas market fail to change, no new investments into high-risk projects, such as Polish shale gas, will be made.

To summarise, Poland missed its chance at becoming a country independent of natural gas

Polish Shale Gas “Eldorado” imports. The years ahead should be devoted to improving the law, deposits prospecting and the implementation of technologies appropriate for shale gas extraction. Only with these steps in place and gas prices rising will Poland again be able to dream of being independent of foreign gas providers. Nowadays, the country can merely diversify its gas supply directions, so that armed conflicts or instabilities in certain parts of the world do not affect national security. As the saying goes: ‘The first generation seeks, the second invests and the third collects the profits’. In this particular case it appears to be absolutely correct. 

References [1] [2] [3] [4] [5]

[6] [7] [8] [9] [10] [11] [12] [13]

[14] [15] [16] [17] [18]

Roznhnov K., Should Gazprom fear shale gas revolution?, BBC News, April 2010 Wood Mackenzie Unconventional Gas Service Analysis, Poland/Silurian Shales, August 2009 Vello A. Kuuskraa, Scott H. Stevens, Advanced Resources International Worldwide Gas Shales and Unconventional Gas: A Status Report, December 2009 Gautier D.L., Pitman J.K., Charpentier R.R., Cook T., Klett T.R., Schenk C. J., Potential for TechnicallyRecoverable Unconventional Gas and Oil Resources in the Polish-Ukrainian Foredeep, usgs.gov, July 2012 Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy, Ocena zasobów wydobywalnych gazu ziemnego i ropy naftowej w formacjach łupkowych dolnego Paleozoiku w Polsce – Raport Pierwszy, Warszawa 2012 Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy, Bilans zasobów z kopalin w Polsce według stanu na 31.12.2012 r., Warszawa 2013 Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy, Państwowa Służba Geologiczna – O gazie w łupkach, Warszawa 2013 Zestawienie prac rozpoznawczych za gazem z łupków – zakończonych i będących w trakcie (stan na dzień 03.08. 2015 r.), infołupki.org.pl Ministerstwo Gospodarki, Polityka energetyczna Polski do 2030 roku, Warszawa 2009 Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy, Badania aspektów środowiskowych procesu szczelinowania hydraulicznego wykonanego w otworze Łebień LE-2H, Warszawa 2012 Sedia G., Poland’s Shale Gas Disappointment, The Krakow Post, November 2013 Zestawienie prac rozpoznawczych za gazem z łupków – zakończonych i będących w trakcie (stan na dzień 02.11. 2015 r.), infołupki.org.pl Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy, Ocena zasobów wydobywalnych gazu ziemnego i ropy naftowej w formacjach łupkowych dolnego paleozoiku w Polsce (basen bałtycko-podlasko-lubelski),Warszawa 2012 A.E., Mad and Messy regulation: Shale gas in Poland, economist.com, July 2013 Zestawienie koncesji dotyczących gazu z łupków (stan na dzień 31.07.2015 r.), infołupki.org.pl Zestawienie zakończonych otworów rozpoznawczych za gazem z łupków wraz z rodzajem wykonywanych zabiegów specjalnych (stan na dzień 2.11.2015 r.), infołupki.org.pl Paturej B., Gaz z łupków ulatuje z kraju? „Walka o polskie łupki cały czas trwa.”, onet.pl, February 2015 Wang Z., Krupnick A., US Shale Gas Development – What Led to the Boom?, Resources for the Future, May 2013

Wojciech Patryk Kurowski Bijak

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 How It Works?

Wojciech Kurowski Introduction

Short definition

I am writing this article with reference to my previous publication about “Drilling fluids”. One more time I want to touch the issue connected with fluids which are used in oil and gas industry. As the matter of fact I would like to describe a cushion (buffer fluid) and explain you how exactly it works. As far as I know, for most of you who have never been associated with cementing operations, the name of the cushion can be unfamiliar. Nevertheless, for petroleum engineers this liquid is a substance which allows to correct execution of cementing the annular space.

If we want to consider the simplest definition of the cushion, it will be liquid which viscosity and density is close to crude oil and water. From the technical point, above parameters are not coincidental. The buffer fluid must be compatible with drilling mud and cement slurry. Otherwise, the accomplishment of the sealing stage may be unenforceable.

Tasks In order to avoid complications during the operation of cementing the annular space, properly

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designed cushion has to fulfill several basic functions inter alia: • separate the drilling fluid from the cement slurry, • improve the displacement of the drilling fluid from wellbore, • allow to obtain turbulent flow, • provide appropriate contact time of cement slurry with rocks and pipes.

Properties Every cushion ‘s recipe is prepared individually according to the task it is assigned. The effectiveness of cementing depends primarily on the cushion’s properties inter alia: • small filtration, • thermal resistance, • adjustment of rheological parameters, • no impact on the drilling fluid and cement slurry, • lack of corrosive aggressiveness on pipes and rocks, • keeping weighting materials in suspension.

Types Selection of a suitable type of cushion is determined by the requirements. The basic types of buffer fluids include: • water, • aqueous saturated solution of sodium chloride (HCL) and potassium chloride (KCL), • aqueous solution of hydrogen chloride (HCL), • emulsion and liquid hydrocarbons with addition of dispersants, • aqueous bentonite suspension.

How It Works?

How it works?

Properly designed and compatible cushion is pumped from a buffer tank to drill pipes. It takes place after the end of injection stage of drilling mud. The buffer fluid under pressure flows through the drill pipe to the cementing shoe where it returns. Then it flows back between the casing string and the wall of the hole. After the implementation of the whole volume of the buffer fluid, the cement slurry is injected into the wellbore. Stage of cementing is ended by the creation of cement stone.

During entire period of cementing stage the cushion separates the drilling mud from the cement slurry. Its hydrostatic pressure helps in the expulsion of drilling mud and allows a better cleaning of the annular space. 

References [1] Nafta-Gaz 2016, nr 6, s.413-421, DOI: 10.18668/NG.2016.06.04 [2] Raczkowski J., Stryczek S., Fugiel K., Kraj Ł., Wilk S., Zaczyny do uszczelniania w otworach wiertniczych. Kraków, 1978.

[3] Habrat S., Raczkowski J., Zawada S., Technika i technologia cementowania w wiertnictwie. Wydawnictwo geologiczne. Warszawa, 1980.

[4] Wójcikowski A., Przygotowanie otworów do wiercenia 311[40].Z1.04. Poradnik dla ucznia. Wydawca: Instytut Technologii Eksploatacji – Państwowy Instytut Badawczy. Radom, 2007.

[5] YoungPetro – 18th Issue – Summer 2016.

[6] Photo: www.biarri.com