Recent Laboratory Results of THAI and Its Comparison with Other IOR Processes

Gréaves, M.; Xia, Tian; Turta, Alex; Ayasse, Conrad

doi:10.2118/59334-ms

Cited by 30 publications

(13 citation statements)

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“…Due to the efficient sweep of the reservoirs by the combustion and hot gas fronts. One of the most important benefit of THAI application for heavy oil and tar sand bitumen reser-voirs is that it produces and preserves upgraded oil 17) . In this study, combustion tube conducted vertically (top-down ISC) to use gravity as a force in which used in THAI, so as to minimize gravity segregation effects.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Simulation Study of <i>In-situ</i> Combustion Process in Carbonate Fractured Porous Media

Shojaiepour

Kharrat

Shojaiepour

et al. 2014

J. Jpn. Petrol. Inst.

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According to difficulties of producing heavy oil reservoirs, in-situ combustion (ISC) as one of the high efficient methods leads to reduce oil viscosity by increasing temperature. Since there are remarkable amounts of heavy oil reservoirs in the world and lots of experimental works have been carried out on sandstones, shale or oil sands, the research on carbonate rocks seems to be rare. The experimental tests were performed with the oil of 17.5° API and 8° API mixed with the crushed carbonate rocks of Asmari and Sarvak formations respectively to investigate the feasibility of ISC and calculate its parameters. According to experiments, combustion tube conducted vertically to use gravity as a force to minimize gravity segregation effects. Results show that combustion is technically applicable to the both rock-fluid systems. Additionally the percentages of CO2, O2 and CO have been measured by gas analyzer. Moreover, the effect of grain size on combustion temperature, connate water on oil recovery and front characteristics are investigated. Finally, fractured model of combustion tube is simulated and the effects of air injection rate, permeability, initial oil saturation and grid size are investigated. The obtained basic parameters of experiments are suitable for ISC implementation to fields efficiently.

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Section: Introductionmentioning

confidence: 99%

Experimental and Simulation Study of <i>In-situ</i> Combustion Process in Carbonate Fractured Porous Media

Shojaiepour

Kharrat

Shojaiepour

et al. 2014

J. Jpn. Petrol. Inst.

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“…Channelling 3. Unfavourable gas/oil mobility ratio (7) 4. Lack of initial heated communication paths within the reservoir 5.…”

Section: Introductionmentioning

confidence: 99%

Upgrading Athabasca Tar Sand Using Toe-to-Heel Air Injection

Xia

Gréaves

2002

Journal of Canadian Petroleum Technology

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The unique operation of the THAI (Toe-to-Heel Air Injection) process, enables very high oil recovery and substantial in situ upgrading. Both thermal upgrading (non-catalytic) and also catalytic upgrading, in which a catalyst is emplaced along the horizontal producer well, were investigated. 3D physical model experiments were conducted on virgin Athabasca tar sand bitumen to investigate dry and wet combustion performance. These results were compared against those from a steamflood test, which was subsequently followed by air injection. Excellent ignition, very stable combustion propagation and thermal upgrading of nearly 10 ° API were achieved using Athabasca tar sand. Additional upgrading was achieved using an in situ catalyst. THAI has the extra advantage that some hydrogen is generated in situ, providing further significant upgrading via hydroconversion. There are also substantial environmental benefits because of the large reductions in sulphur and heavy metals in the produced oil. Furthermore, oil is produced without "displacement delay," immediately ahead of the combustion front. The oil recovery using THAI was greater than 75% OOIP. Introduction The world's conventional crude oil production is expected to reach its peak in the second decade of this century and enter a permanent decline phase(1). The composition of the oil barrel is getting heavier, and diluent blending "stop-gaps," assisted by very limited coker upgrading capacity will, eventually, be insufficient to cope with the increasing demand for light oil. Historically, heavy oil trades at a substantial discount to that of premium light crude oil. Therefore, it has lower economic value and also market potential, unless new technology is developed to upgrade it to lighter oil, in an economic manner. The Athabasca Tar Sand deposit of northeastern Alberta, Canada, is one of the largest reserves of bitumen in the world. These are estimated to be 212.9 ??109 m3 (1,339 ?109 bbl)(2). Although about 10% of the bitumen reserves are mineable, the rest of the Athabasca Tar Sands have to be exploited by in situ recovery technology. A number of in situ oil recovery methods, such as steam assisted gravity drainage (SAGD)(3) and in situ combustion (ISC)(4, 5), have been extensively studied, both in the laboratory and in field tests. In situ combustion (ISC) is a thermal EOR method, in which a small fraction of the oil (or coke) in the oil layer is burned in order to mobilize the unburned fraction. Due to the strong exothermic oxidation reactions between hydrocarbon (or coke) and oxygen, the temperature of the oil-bearing matrix in the combustion zone is 500 to 700 °C, which is much higher than in steam flood processes (150 to 250 °C). High temperatures are very favourable for tar sands and heavy oil reservoirs, because not only is the oil viscosity reduced by several orders of magnitude, but the heavy residue is also thermally cracked to lighter compounds.

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“…The way in which the mobile oil zone operates is also responsible for preserving downhole upgrading, since oil is immediately produced via the open section of the horizontal producer well, instead of being displaced into the downstream oil layer. Details of THAI are given by Greaves et al (1)(2)(3) .…”

Section: Introductionmentioning

confidence: 99%