Study on Water Reduction, Oil Stabilization and Efficiency Enhancement in Complex Fault-Block Oilfield at the Late Stage of High Water Cut Development

As the mature oil fields have stepped into the high water cut stage, the remaining oil is considered as potential reserves, especially the attic oil in the inclined fault-block reservoirs. A novel assisted gas–oil countercurrent technique utilizing gas oil countercurrent (GOC) and water flooding assistance (WFA) is proposed in this study to enhance the remaining oil recovery in sealed fault-block reservoirs. WFA is applied in our model to accelerate the countercurrent process and inhibit the gas channeling during the production process. Four comparative experiments are conducted to illustrate enhanced oil recovery (EOR) mechanisms and compare the production efficiency of assisted GOC under different assistance conditions. The results show that WFA has different functions at different stages of the development process. In the gas injection process, WFA forces the injected gas to migrate upward and shortens the shut-in time by approximately 50% and the production efficiency improves accordingly. Compared with the basic GOC process, the attic oil swept area is extended 60% at the same shut-in time condition and secondary gas cap forms under the influence of WFA. At the production stage, the WFA and secondary gas cap expansion form the bi-directional flooding. The bi-directional flooding also displaces the bypassed oil and replaced attic oil located below the production well, which cannot be swept by the gas cap expansion. WFA inhibits the gas channeling effectively and increases the sweep factor by 26.14% in the production stage. The oil production increases nearly nine times compared with the basic GOC production process. The proposed technique is significant for the development of attic oil in the mature oil field at the high water cut stage.

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A Study on the Development Technology of Sidetracking Wells in Fault Block Reservoirs During the High Water Cut Stage

Petroleum Science and Technology ◽

10.1080/10916466.2010.516295 ◽

2013 ◽

Vol 31 (5) ◽

pp. 465-471 ◽

Cited By ~ 2

Author(s):

C. Chuanzhi ◽

Z. Xiaoyan

Keyword(s):

High Water ◽

Fault Block ◽

Development Technology ◽

High Water Cut Stage ◽

High Water Cut ◽

Water Cut

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Dual Completion Petroleum Production Engineering for Several Oil Formations

Management Systems in Production Engineering ◽

10.1515/mspe-2018-0035 ◽

2018 ◽

Vol 26 (4) ◽

pp. 217-221

Author(s):

Tanyana Nikolaevna Ivanova ◽

Aleksandr Ivanovich Korshunov ◽

Vladimir Pavlovich Koretckiy

Keyword(s):

Production Technology ◽

Oil Recovery ◽

Late Stage ◽

Recovery Rate ◽

High Water ◽

Production Engineering ◽

Petroleum Production ◽

Cost Efficient ◽

High Water Cut ◽

Water Cut

Abstract Cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. One of the easiest but short-term ways to increase oil production and incomes at development of oil deposits is cost of development and capital cost reduction. Therefore, optimal choice and proper feasibility study on the facilities for multilayer oil fields development, especially at the late stage of reservoir working, is a crucial issue for now-day oil industry. Currently, the main oil pools do not reach the design point of coefficient of oil recovery. The basic feature of the late stage of reservoir working is the progressing man-made impact on productive reservoir because of water injection increasing for maintaining reservoir pressure. Hence cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. To address the above concerns the dual completion petroleum production engineering was proposed. The intensity of dual completion of formation with of different permeability is determined by rational choice of each of them. The neglect of this principle results a disproportionately rate of highly permeable formations development for the time. In effect the permeability of the formations or their flow rate is decreasing. The problem is aggravated by lack of awareness of mechanics of layers' mutual interference in producers and injectors. Dual completion experience in Russian has shown, that success and efficiency of the technology in many respects depend on engineering support. One of the sufficient criteria for the choice of operational objects should be maximal involvement of oil-saturated layers by oil displacement from seams over the economic life of well producing oil. If it is about getting high rate of oil recovery for irregular formations there is no alternative to dual completion and production. The recommended dual completion petroleum production technology enables development several formations by single well at the time. The dual completion petroleum production technology has been more important than ever because it is right not only for formations but for thin layers with undeveloped remaining reserves.

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