Use of Horizontal Wells for Improving Steamflood Performance of a Thin, Low-Permeability Heavy-Oil Reservoir

Sarkar, Amit Kumar; Sarathi, Partha; Strycker, Arden R.

doi:10.2118/27806-ms

Cited by 2 publications

(2 citation statements)

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“…In vertical wells, high injection pressure and limited heating range of steam injection will come out, which results in a limited development potential of heavy oil reservoirs. However, horizontal wells are proved to be effective in developing heavy oil reservoirs, such as enlarging the heat exchange areas of steam and reservoirs, enhancing the thermal efficiency of steam, decreasing the steam injection pressure in wells, increase the productivity of oil wells, inhibiting the water invasion of edge and bottom water, and extending the production time (Petit et al 1989;Sarkar et al 1994;Zerpa 1995). During the development process of super heavy oil reservoirs by chemical agent Mokrys 1991, 1993) such as dissolver and hydrocarbon solvent assisted steam, chemical agent can break the macromolecular structure of asphaltenes, decrease oil viscosity and oil-water interfacial tension, increase flowing ability of super heavy oil, and then decrease injection pressure of subsequent injected steam (Luigi et al 1994;Pradeep et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional physical simulation experiment study on carbon dioxide and dissolver assisted horizontal well steam stimulation in super heavy oil reservoirs

Wang

Liu

Wang

et al. 2016

J Petrol Explor Prod Technol

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There is abundant super heavy oil resource in the world, however, due to the very high viscosity and density, conventional steam stimulation process will result in high steam injection pressure and small heating area, leading to very bad development effect. To improve the development effect of steam injection in super heavy oil reservoirs, a compound stimulation enhanced thermal recovery technology is proposed. Steam injection is conducted through horizontal well assisted by carbon dioxide and oil-soluble composite dissolver, so this kind of technology is called HDCS for short. HDCS technology synthetically utilizes the physical and chemical characteristics of dissolver, carbon dioxide and steam, so that viscosity reduction, mixing and mass transfer, increasing energy and assisting cleanup of the three components are combined. In this paper, three-dimensional thermal recovery physical simulation experiment apparatus is used to conduct the comparison experiments between steam stimulation and HDCS stimulation, to analyze the development advantage and mechanisms of HDCS stimulation. Experimental results indicate that HDCS stimulation realizes the rolling replacement of viscosity reduction effect of dissolver, carbon dioxide and steam, keeping the oil in steam front with a low-viscosity, and enlarging the viscosity reduction range of super heavy oil by steam injection. Besides, the dissolver injection beforehand decreases the subsequent steam injection pressure, and the dissolution and release of carbon dioxide in super heavy oil can complement the reservoir energy. Compared with the condition after conventional steam stimulation, after HDCS stimulation the steam has larger swept volume and heating range, and the content of heavy component and viscosity of crude oil decreases by larger amplitude. The properties of super heavy oil are improved better than conventional steam stimulation. HDCS stimulation significantly improves the development effect of steam in super heavy oil reservoirs.

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Section: Introductionmentioning

confidence: 99%

Three-dimensional physical simulation experiment study on carbon dioxide and dissolver assisted horizontal well steam stimulation in super heavy oil reservoirs

Wang

Liu

Wang

et al. 2016

J Petrol Explor Prod Technol

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“…Many papers investigated increasing the oil interval contact through horizontal wells in the early years of development (Joshi 1988;Sarkar et al 1994). After studying these previous experiences, our team accepted that horizontal well technology should be the solution for XLT thin, heavy oil reservoir.…”

Section: Introductionmentioning

confidence: 99%

An Effective Way to Develop a Thin-layered Heavy Oil Reservoir within Economic Margin

Ren¹,

Sun²,

Yu³

et al. 2012

All Days

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More than 50% of the heavy oil resources for PetroChina Liaohe exist in thin (approximately 3-to 8-m thick) reservoirs. For this type of reservoir, steamflooding with conventional vertical wells is not economically profitable, and in-situ combustion methods are not applied because of operational difficulties. Horizontal well technology brought a new direction to attempts to improve technical and economic performance of steamflood operations. Many experiments had been conducted to use the technology in the Liaohe oil field to achieve economic production, but the expected results were still not achieved. Lessons learnt indicate that the root cause is the poor oil contact of the horizontal wells' trajectories in the thin, heavy oil reservoir. A pilot project was conducted to explore whether horizontal well technology in combination with optimized cyclic steam stimulation could deliver economic production from these thin heavy oil reservoirs. Horizontal well placement was accomplished by using near-bit azimuthal measurements and images.Both the feasibility and economic performance of the technology have been studied in this five-well pilot project. Comparing the performance of these five wells to the previous ones, the results indicate that 1) The well-placement drilling solution can maximize the oil contact up to an average 91% of net-to-gross coverage.2) The well-placement drilling solution improved drilling efficiency by 40%.3) The drilling operation was conducted with no nonproductive time (NPT), compared to the previous NPT maximum of 6 days. 4) The well-placement drilling solution did keep the cost flat, and the cost even slightly declined. 5) The optimized cyclic steam stimulation in well-placement-drilled wells can decrease the cyclic steam stimulation cost over production to 1000 RMB/ton, which is recognized as an economic ideal in the industry. 6) The daily block production has increased from 20 tons/day to 72 tons/day after using the combined wellplacement-drilling and cyclic steam stimulation technology, which is an increase of 210%. 7) The income/input ratios at the end of the fourth year for the two better wells are both 1.48 (reaching a balance at the second and third years, respectively), and ratios for all five wells ratios averaged 0.93, which means the wells will earn net money at the beginning of the fifth year. Compared to the ratio of 0.03 for a previously drilled well, this is not only a big financial improvement, but is also an incentive to revitalize many similar thin heavy oil reservoirs because it proves the possibility of developing them within the economic margin. The success of the pilot project proved to us that horizontal well-placement drilling in combination with optimized cyclic steam stimulation is an effective way to develop thin-layered heavy oil reservoirs within the economic margin in Liaohe oil field. We extended this horizontal well technology to other blocks and have achieved repeated success.

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Use of Horizontal Wells for Improving Steamflood Performance of a Thin, Low-Permeability Heavy-Oil Reservoir

Cited by 2 publications

References 11 publications

Three-dimensional physical simulation experiment study on carbon dioxide and dissolver assisted horizontal well steam stimulation in super heavy oil reservoirs

Three-dimensional physical simulation experiment study on carbon dioxide and dissolver assisted horizontal well steam stimulation in super heavy oil reservoirs

An Effective Way to Develop a Thin-layered Heavy Oil Reservoir within Economic Margin

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