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Athabasca Oil Sands, Alberta

Introduction

Athabasca oil field is located in Alberta around Fort McMurray. It is one of the largest oil field in Canada. The Athabasca river play a vital role in the mining process and the Athabasca oil field is located in the heart portion of the Athabasca River, Alberta. The contaminated water from that derived after the mining process cannot e returned back to the river and this water could be diverted in to the tailing ponds. This is done to prevent the environmental hazard and thereby prevent the pollution of water. (Government of Alberta, 2008)

History and Discovery of the Athabasca Field

Before the arrival of Europeans the Athabasca area was occupied by First Nations and Metis people. Alexander Mackenzie crossed the Athabasca Rivers in 1792, and described the oil sands in the river. David Thompson and John Franklin did a survey of the area for twenty years from 1799. The primary geological assessment of Athabasca oil sands was done in 1848 by Sir John Richardson. Dr. Robert Bell evaluated the samples of the Athabasca oil sands in 1882 for the Geological and Natural History Survey of Canada (He was the director of the organization at that time). He then commenced experiments using hot water to separate the bitumen from the sand. Bell recommended a method to separate bitumen from the sand by a hot water separation process. In his opinion it would be viable and constructing a pipe-line could help to transport the extracted crude oil from the Athabasca Lake to the Hudson’s Bay to the international markets (Hein, 2005).

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R. G. McConnell of the GSC (Geological Survey of Canada) provided a geographical description of Athabasca oil sands in 1888, and linked with the Cretaceous Dakota sandstone oil sands which is situated in the Western Interior Basin of the USA. The Canadian parliament sanctioned a funding of $7,000 to McConnell to employ a contractor, drill a rig, and to move the tools up to the area. They started drilling the well on 15th of August 1894, and the drilling reached a depth of 1,600. He drilled another well in 1897 from the Red-water town site along the North Saskatchewan River banks. Count Alfred Hammerstein did drilling in the area for four years from 1906 guessing to hit a large subsurface oil pool that he believed under the layer of oil sands. Even though he did not find any oil, he did find salt at the area where the Athabasca and Horse rivers merge (Hein, 2005).

In 1913 Sidney Ellis known as ‘Father of the Oil Sands’ gathered a group to commence a thorough survey of the oil sands in the River valley. He collected a lot of oil sands from Fort McMurray in 1915 and transported it to Edmonton within twenty one days. With the backing from Max Bal, he effectively drilled and processed oil sands in the Ruth and Mildred Lake area in 1926 (Hein, 2005).

Max Bal got a six-section tenancy on Horse River in 1936 and he had constructed an extraction plant there. The Abasand separation plant was constructed in Fort McMurray along the Horse River in 1940. This plant processed around 19K ton sand and yielded 17K ton bitumen in the year of 1941. This bitumen would then re-processed into fuel-oil, coke, petrol and diesel. Federal authorities seized the plant in 1942 and commenced a drilling and extraction program to charter the reserves for the 2nd world war exigence plans. The Mines Branch finalized the drilling by the year of 1947 and estimated that there is around 1750 million ton commercial grade oil reserves there. But the Alberta province government opened the Bitumount plant again in 1948. The plant had a production capacity of 3500 tons per week. They also completed Clarks hot water separation method which is a commercial test of the extraction technique (Hein, 2005).

In 1962, The Alberta Oil and Gas Conservation Board gave permission to the Great Canadian Oil Sands Ltd. to produce around 31500 barrels of oil for each day from the plant of Tar Island. The company opened their primary oil sands plant in 1967. The developed a method to economically extract bitumen and oil sand products and later upgraded to crude oil successfully. In 1950 a co-company of Imperial Oil known as Royalist initiated a much more solid exploration, expansion and manufacture in the oil sands of McMurray. Alberta Oil and Gas Conservation Board received an application from the Shell oil company to start bitumen production. The expected production capacity was around 130000 barrels each day and the production is by in situ process.  Also, The Energy Resources Conservation Board of Alberta had received another application from them in 1978 to produce 100000 barrels each day in mining operation (Hein, 2005).

AOSTRA (Alberta Oil Sands Technology and Research Authority) was formed in 1974.The purpose of this organization is to deliver the government funds and to organize things for bitumen mining and upgrading studies. In 1984, they constructed an Underground Test Facility (UTF) near to the project site of Dover River which was ran by North-star Energy Limited. The facility was used to test horizontal wells and SAGD (Steam Assisted Gravity Drainage) to extract bitumen from the oil sands. More than sixty percent of the bitumen was recovered by the year of 1990. The B Phase of the project began its pre-commercial testing in the year 1991 (Hein, 2005).

In 1998 there were 0.34 billion metre cubes of established reserves of crude bitumen under active development for surface mineable and 0.24 billion metre cubes for in-situ process schemes. The Imperial Oil Company conducted the first SAGD experiment in 1985 at the Production Project of Cold Lake. This actually discovered the ability of in situ thermal process to easily recover bitumen from oil sands. Several steam assisted gravity drainage projects have been developed after this in the Cold Lake and Peace River due to the concerted effort of AOSTRA and UTF (Hein, 2005).

Currently, the Cold Lake Production Project is the world’s biggest in situ oil sands steam generation and bitumen-production operation. It has a production around 100000 barrels of bitumen each day averaging around 35 million barrels in an year. Present-day, the CCS (cyclic steam-stimulation) process used in Cold Lake. The bitumen shipped by pipeline mostly to markets in the United States of America and to Canadian refineries (Hein, 2005).

Description of Reservoir

Athabasca is a bitumen rich field which is among the four major oil deposit in Alberta north. These deposits have total reserves estimated at more than 1.7 trillion barrels which is almost 40% of the world’s resources of bitumen. (Masson & Remillard, 1995).

In 1995, 1996 and 1997 drilling and production of bitumen and synthetic crude oil from the oil sands reached record levels in Alberta.  Synthetic crude oil production from bitumen production in the mineable area of the Athabasca deposit was 18.8 million cu.m in 1999.

As per the studies by Energies and Utilities Board in 2000(EUB) the ultimate volume of crude bitumen in place in Alberta is about 400 bcm , among the volume about 24 billion cubic metres, it can be recovered by surface mining technology. But the remaining volume of crude bitumen occurs in areas with thick over burden. Even it is a burden it can be recovered by in situ thermal recovery or under ground mining. New analysis from EUB states that the ultimate recovery potential of crude bitumen is increased up to 49 billion cubic metres ( Hein, Langenberg, Kidston, Berhane, & Berezniuk, 2001)

Athabasca area contains about 900×109 barrels of bitumen. This resource can be enlarged through thermal in situ techniques and surface mining.The Oil Sand Developers of Alberta in 1988 predicted that conventional and non conventional recourses will grow in next century ( Hein, Langenberg, Kidston, Berhane, & Berezniuk, 2001) (Hubbard & Jensen, 2011)

Athabasca field and McMurray formation

McMurray formation is formed at the period of Aptian age or lower. When deals with lithology  the McMurray Formation consists of fine to coarse grained quartzitic sand and sandstone, mud, clay and, thin coal beds.

The above figure illustrates the Schematic cross section, Fort McMurray area ( Hein, Langenberg, Kidston, Berhane, & Berezniuk, 2001)

Description of the reservoir deposit

The sediments that are appearing is actually came from the Canadian shield to the east and deposited in large fresh water lakes and rivers. After a certain period of time these lakes were replaced by marine oceans in which the overlying Clearwater shale was deposited. The Athabasca sand body thickness ranges from an average of about 150 to a maximum of over 200 feet in thickness. It consists of unconsolidated sand diversify with clay and shale partings of variable thickness.

There is an aquifer underlying on the extreme east side of the reservoir or deposit, and there are small and free-gas accumulations in the south-centre part. However Athabasca sand body contains no continuous water zone and has no gas cap. (Govier, 1965)

Character of reservoir hydrocarbon

Among Alberta oil field the oil of the Athabasca oil sands is very different and unique. The oil in this field is of naphthenic base. It contain large amount of sulphur, heavy and viscous. Commonly oil’s API gravity is ranging from 10 to 11.5°, but here it is as low as 6.50 in some area in McMurray. (Govier, 1965)

Areas in McMurray have many data’s about viscosity of oils, but it can be said that the crude oil is almost immovable at reservoir temperature that is maximum of about 90°F throughout the deposit. (Govier, 1965)

It is a fact that the amount of recoverable synthetic crude oil from the deposit of 267 billion barrels are equivalent to almost twice the total world petroleum consumption. (Study done in 1965).

The oil-in-place averages almost 100,000 barrels per acre over the entire Athabasca oil sand deposit. It is not uncommon to find a 100 foot section of oil sand averaging 12 weight per cent of oil. In such a situation, the oil-in-place would be 180,000 barrels per acre, comparable with the richest “conventional” oil field in Alberta.

In 1963, the comprehensive report published by Alberta Oil and Gas Conservation Board  about reserves of oil, in the oil sands of Alberta including the Athabasca deposit.

 Table 1 represents a tabulation of the Athabasca reserves comes under three oil saturation categories. The rich sands includes, more than 10 weight % of oil, and the lean sands and intermediate sands consists of 2 to 5 % and 5 to 10 % correspondingly.

Table 2, also represents a tabulation of reserves depends on the depth of overburden. Almost 10 % of the estimated recoverable reserves of upgraded oil are shown to have less than 100 Ft. of overburden cover, while 75 % have greater than 250 Ft. of cover.

Table 1

Saturation distribution of Athabasca oil sands reserves(Govier, 1965)

WEIGHT SATURATION CATEGORY

OIL IN PLACE

RECOVERABLE RAW OIL

RECOVERABLE SYNTHETIC CRUDE OIL

Rich sands

(Greater than 10%)

440.8

260.5

188.3

Intermediate sands

(5 – 10 %)

145.7

85.5

61.9

Lean sands

(2-5 %)

39.4

23.1

16.7

Total

(Greater than 2 %)

625.9

369.1

266.9

Table 2

Distribution of Athabasca oil sands reserves by overburden thickness(Govier, 1965)

OVERBURDEN FEET

OIL IN PLACE

RECOVERABLE RAW OIL

RECOVERABLE SYNTHETIC CRUDE OIL

0-50

12.4

10.5

7.4

50-100

32.7

27.8

19.6

100-250

75.5

52.8

37.8

250-500

88.9

48.9

35.6

500-1000

209.4

115.2

83.7

1000-1500

171.6

94.4

68.6

1500-2000

35.4

19.5

14.2

Total

625.9

369.1

266.9

Description of Reservoir Fluids

Canada is the second largest in oil reserves in the world out of which Athabasca field is one of the largest in the country. In this field oil sands are prominently found and these oil sands are a combination of crude oil, bitumen, clay, sand and water. In which bitumen is mostly found which about 180 billion barrels is. Although the amount of bitumen may vary according to the geographical differences. It can vary from one to 20 percentage. But they are typically around 10% and the left overs are 83% of silica sand, 4% water and 3% fluvial clay.

These bitumen resources are believed to be found in the parts of north eastern and is because of the migration of light crude from southern Alberta. These same geological forces influenced a lot for the development of the Rocky Mountains. Gradually it being turned into more crude bitumen over time. These deposits gradually deposited in the basins within the Devonian strata. This is subsequently modified because of the rising sea levels which is occurred in early cretaceous. Hence different aquatic animals and plants can be seen in the sedimentary rocks which is mainly migrated through estuarine and also the marine shoreline.

Figure above is the location of the Canadian maps oil sands (CERA, n.d.)

In this area there is a belt of some 40-60 meter is formed and the oil sands are under the flat clay, sand and limestone. Sometimes it is covered with water logged surface layer between one to three meters deep. The surface mining of 10% of bitumen is possible in Athabasca field is because it covers an area of about 3400 km2. This is relatively shallow overburden of less than 75 meters. These surface extension makes it to mine these areas without any problem.

It is found that of about 176 billion barrels of reserves are found in this oil filed. Out of which 174 billion barrels of bitumen and 1.6 billion barrels of crude oil. In this a total recoverable reserve put at 335 billion barrels (315 and 19.7 billion barrels respectively). (CERA, n.d.)

The above figure is the anatomy of an oil sand deposit (Oil Sands Magazine, 1970)

Bitumen is a highly viscous fluid and complex hydrocarbon found within the oil deposits. It is also classified as extra heavy oil. It is having an API gravity of about 8o. It is almost found as solid at room temperature. In this bitumen sulphur content is discovered and it is about 4 to 5%. It also consists of slight traces of heavy metals mainly nickel and vanadium. Bitumen can be subdivided into two organic compounds which is asphaltenes and maltenes.

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Asphaltenes are major component for imparting high viscosity of the oil. This is because of their complex molecular structure. It also makes the bitumen heavy and sticky and makes the fluid with nickel, sulphur and vanadium. These components reduce the quality of the normal crude and these enhancers make the bitumen harder to process in a conventional refinery. Athabasca bitumen almost consists of 14 to 18% of these types of asphaltenes and the processing of these fluids is very complicated.

Furthermore, maltenes can be again subdivided into three sub groups. They are saturates, aromatics and resins. The fraction of these variables varies according to the different types of subsurface properties. (Oil Sands Magazine, 1970)

To get the better insight of the bitumen fluids from the Athabasca field, then we have to do different experiments like compositional analysis and molar mass and density.

Compositional analysis and molar mass of Athabasca’s reservoir fluid

In compositional and molar mass analysis, Gas chromatography (GC) technique has been used to understand the composition of Athabasca’s. In general, the crest formed in the gas chromatography is studied to distinguish the alkane contents in this bitumen. The compositions are found in combined format as C11+ C12 to C37+ C38. It is very difficult to distinguish the compositions above C38. So heavier fractions are given and joined together as C39+. To determine the molar mass of the reservoir fluid in Athabasca, cryoscopy technique is used using a Roebling Kryometer. In this method, certain amount of oil is weighed and it is added with benzene. Then, we can find out the depression of the made solution by measuring the freezing point of the made solution and then compare it with the relative freezing point of the pure benzene. Finally we will get the molar mass of prepared solution.

Density

Oil density measurement is very important to understand the different components in the crude oil that is bitumen found in Athabasca. For this Anton Paar apparatus is used to understand the density of the reservoir fluid. For this high pressure and temperature conditions are applied to get appropriate values. (Yaser, Mohammad, Hassan , & Ole, 2012)

The above table helps to understand the different compositions found in Athabasca’s bitumen. (Yaser, Mohammad, Hassan , & Ole, 2012)

Types of well drilled and completions typically used:

In Alberta oil sands production takes place in mainly 3 regions: Athabasca, Cold Lake, and Peace River.  Lionshare of mining activities and production takes place in Athabasca. It includes Steam Assisted Gravity Drainage (SAGD), Cyclic Steam Stimulation (CSS), and Enhanced Oil Refining (EOR) in situ projects. There are also several off-gas refinery projects and primary projects. (BOARD, 2017)

Many changes were brought in to the mining activity by the first large scale mining in the Great Canadian oil sands. This include bucket-wheels that were brought from the coal mining industry. When Syncrude started its operation in 1978, oil sand exploitation was done by the introduction of large conveyor lines. This has led to a greater productivity relative to the time and expense as well as selectivity that were offered by truck and shovel mining. All kinds of electric and hydraulic shovels, excavators, haul trucks and dozers are used from major manufacturers like Caterpillar and Komatsu. Moreover, optimisation of the different production operations is done by the effective use of wireless network communication, Global Positioning System and dispatching systems. The use of in-situ alternatives are gaining importance due to the fact that 80% of oil sands resource are found too deep so as to use open pit mining. Open pit mining will soon be replaced by these extraction techniques as the main source of production of bitumen from oil sands. But as for now, these extraction techniques are in its early phase. (MINING TECHNOLOGY, 2018)

At present, Steam Assisted Gravity Drainage (SAGD) is the most used in-situ method. Steam is injected in to the deposit through drilled holes. This injected steam heats the oil sand and thereby reduces the viscosity of the bitumen. Later these bitumen moves slowly towards the drilled wells. This allows it to migrate to the surface and without the sand. Cyclic steam stimulation (CSS), vapour extraction (VAPEX) and toe-to-heel-air-injection (THAI) are also used. (MINING TECHNOLOGY, 2018)

 The following three methods are used to produce Bitumen in Alberta:

Surface mining using trucks and excavators.

In situ techniques like Steam Assisted Gravity Drainage (SAGD)or Cyclic Steam Stimulation (CSS).

Primary production and enhanced oil production (EOR) in which the bitumen production is similar to conventional oil wells. These methods require no steam. (BOARD, 2017)

Mining was the largest form of extraction in many of oil sands in Alberta. But, only 20% of oil sands can be accessed by mining. Only in situ techniques can be used to access the remaining 80% of oil sands. In 2012, in situ production became the most common extraction method surpassing mining and this trend is expected to continue. About 62% of raw bitumen production is expected to be accounted by in situ in 2040.

Fig source: (BOARD, 2017)

There are mainly three types of in situ recovery technologies that has been included in this report. These are SAGD, CSS, and EOR.

SAGD mainly uses different pairs of horizontal wells for the production of bitumen. For heating the bitumen steam is injected in to the upper well, which is drained in to lower well by gravity and is pumped to the surface.

CSS also uses steam for the production of bitumen. Steam is injected in to the reservoir over a period of several months. This steam heats the bitumen and thereby reduces its viscosity. After some months, a mixture of water and bitumen flows back to the well. The process is repeated for the purpose of economic feasibity of project. (BOARD, 2017)

EOR is used to extract oil from the reservoir when the pressure falls so low that natural production is no longer economically feasible. (BOARD, 2017)

In the 1920s Dr Karl Clark while working for Alberta Research Council developed the first process to produce bitumen from oil sands. It was done on a commercial basis. Many variations of this approach have been used to remove aerated bitumen from the different components of oil sand. And this takes place within the gravity settling vessels. Large amount of money is required for this process. But the energy gains make it viable. According to the reports from National Energy Board, it requires 33m³ of natural gas so as to extract one barrel of bitumen from oil sands by the application of in-situ techniques. Inorder to decrease the bitumen’s viscosity, steam or solvents like butane or propane are used. (MINING TECHNOLOGY, 2018)

In future, when gas reserves get finished, bitumen gasification will become the eventual way ahead. Bitumen gasification is a process that converts bitumen in to synthetic gas to generate its own fuel. Bitumen is a complex long-chain hydrocarbon molecule, which consist of large amount of carbon and less amount of hydrogen. So inorder to increase the amount of hydrogen, upgrading is necessary. It involves many steps like coking, distillation, catalytic conversion and hydro-treatment. All these steps are aimed at the remove sulphur and nitrogen and addition of hydrogen. Bitumen is recovered through wells as the reservoir is very deep to make surface mining possible. (MINING TECHNOLOGY, 2018)

Surface installation/equipment in place

Various kinds of equipments are used in the oil mining field. The equipments are drilling equipment, workover equipment and the production equipment. These equipments are usually installed in the Athabasca mining field. (Control, 2009) The equipments play important role in the mining process. The installation of the equipments is described below.

This is a machine or equipment that is used for the creation of hole or used for the burial purpose. The holes produced by this equipment are called as the boreholes or shaft in the ground. Massive structured rings are used for the drilling purpose. This drilling equipment can be also used for the drilling purpose of drilling the water wells, natural gas extraction wells and also for the drilling of oil wells. Another important purpose of this drilling machine is the installation of sub-surface fabrications. Example of such surface installation methods are instrumentation, underground utilities and so on. The drilling equipments are usually attached with trailers, tracks or the trucks or some permanent structures such as marine based one. These are commonly known as off shore oil rigs. (Control, 2009)

The major equipment in the solid control equipment is the shale shakers, centrifuge, desilters, digasters, mud cleaners, mud gas separators, sand pumps and shearing pumps. China is the well-known company for the solid control equipment. (Control, 2009)

It is an important equipment that used in the Athabasca oil field. The work over rings is mainly of two types: Offshore and onshore workover rings. Caterpillar diesel engines are used as the service depth that installed on the workover rings. The transmission is usually done between 8000ft to 30000ft. (Control, 2009)

The major drilling equipments are Masts, drawworks, crown blocks, substructures, hooks, and hook blocks, rotary tables, travelling blocks, top drives and swivels. The load that the drilling equipment can afford ranges between 190 tons to 1000 tons. (Control, 2009)

This equipment is mainly used to circulate the drilling fluid. The mud pump is a device that is with a purpose of plunging or reciprocating. The fluid is circulated with a pressure under 7500 psi. This equipment is available in different sizes and variable configurations. Commonly used mud pumps are of triplex type. In ancient period, duplex types were used. The duplex mud pumps have two piston or two plungers. A latest model of mud pump is known as hex pump with six piston or plungers are on development. (Control, 2009)

Two types of well control equipments are used commonly. They are Shaffer and Cameron. These are blowout preventers. The equipment consists of choke manifolds, BOP closing units and kills manifolds. (Control, 2009)

Future economics for field 

Budget of Athabasca (2018): Capital budget is $140 that includes $70 for the thermal oil and light oil. The production outlook for the Athabasca oil field is planned as11% of the share of one year. Around $375 million dollars are funded for a sustainable financial position and finally $80 million dollars is planned to spend for improving the commodity prices. These are the highlights of the economics planned in the year 2018 by Athabasca oil field. (Cooperation, 2018)

The updated strategic plan of Athabasca includes the following. According to the three year statistics, the Athabasca oil field is at the position of excess production of oil and that referred to as more than 40,000. The well executed and coordinated work of the company is the reason for the well growth and profit of the company. The main aim of the is to improve the share holders and the profitability of the company. According to the study conducted by the corporate production in the month of November, the production of thermal oil in the Athabasca oil is raised to the value of 30,500 and this is the field estimate that obtained from the study. (Cooperation, 2018)

2018 budget and financial outlook of the Athabasca is determined as around $140. This is approved by the Athabasca’s budget board. The budget is planned for the 2018 year. The company also aims for the increase in the profit of around 11% of the total production profit of the company. Next budget is formulated in the thermal oil production of the company. It is planned around $70 million dollars.

 This profit shares an average of 2% of the total profit of the production of the company. (Cooperation, 2018).

Conclusion

Athabasca oil filed in Alberta is the one of the major bitumen producing oil field in the world. It is very expensive to extract the oil deposits from this field. The second most problem is to refine the extracted oil to pure petroleum products. However, technological advances helped the Canadian petroleum industry to grow. While environmental and political issues have significant impacts on oil production.

References

Hein, F. J., Langenberg, C. W., Kidston, C., Berhane, H., & Berezniuk, T. (2001). A Comprehensive field guide for facies characterization of tha Athabasca oil sands,North East Alberta.

(2018). Retrieved from MINING TECHNOLOGY: https://www.mining-technology.com/projects/athabascasands/

Alberta, G. o. (2008, February 27). Alberta’s Oil sands 2006. Retrieved from Government Of Alberta: http://aep.alberta.ca/water/programs-and-services/river-management-frameworks/athabasca-river-water-management-framework.aspx

BOARD, N. E. (2017). Canada’s Energy Future 2017 Supplement : Oil sands.

CERA, I. (n.d.). Rigzone. Retrieved from Cambridge Energy Research Associates (CERA) .

Control, G. S. (2009, october 3). Mud Solids Control Equipment. Retrieved from GN Soilds Control: http://oilfield.gnsolidscontrol.com/oil-field-drilling-rig-equipment-complete-list/

Cooperation, A. O. (2018). Athabasca Oil Cooperation Outlook 2018. Retrieved from Athabasca Oil Cooperation: https://www.atha.com/upload/press release/156/d08254562d11/athabasca-oil-corporation-announces-2018-second-quarter-results.pdf

Devold, H. (2013). Oil and Gas Production Handbook. An Introduction To Oil and Gas Production, transport,refining and petrochemical industry.

Government of Alberta. (2008, 02 27). Alberta’s Oil Sands 2006.

Govier, G. W. (1965). THE ATHABASCA OIL SANDS.

Hein, F. J. (2005). Historical Overview of the Fort McMurray Area and Oil Sands Industry in Northeast Alberta. Edmonton: Alberta Energy and Utilities Board.

Hubbard, S. M., & Jensen, L. J. (2011). Sedimentology and stratigraphic architecture of a point bar deposit, Lower Cretaceous McMurray Formation, Alberta, Canada.

Masson, R., & Remillard, B. (1995). “Alberta’s New Oil Sands Royalty System,”.

Oil Sands Magazine. (1970, July 04). Retrieved from Oil Sands Geology & the Properties of Bitumen: https://www.oilsandsmagazine.com/technical/properties

Yaser, S., Mohammad, A., Hassan , K., & Ole, T. (2012). Experimental analysis of athabasca bitumen properties and field scale numerical simulation study of effective parameters on SAGD performance, 141-142.