Research on Remaining Oil Development Using Horizontal Well Technology in Low Permeable Reservoir of BaoBei District, BaoLang Oilfield
|School||China University of Geosciences|
|Course||Oil and Gas Field Development Project|
|Keywords||Baolang Oilfield Permeability reservoir Remaining oil development Horizontal well technology|
Baobei Block Baolang Oilfield geographically located in the Xinjiang Bayingolin Mongolia Autonomous Prefecture Yanqi Hui Autonomous County Yongning Township territory constructed position is located in the northern part of Yanqi Basin Bohu Depression depression Baolang hematoxylin northern tectonic belt lithologic control of the North West - - south trending anticline. 12-14% average porosity, the average permeability 2.97-27.3 × 10-3μm2, is a typical low porosity and low permeability reservoir types. The natural reservoir energy edge water-based, developed advance to maintain high oil production rate, now entered a stage of fast decreasing, the overall high moisture content. This complex relationship of the area of ??the underground oil and water, remaining oil distribution regularity, the remaining oil is facing many problems. Oilfield expect to carry out the pattern adjustment by small-scale or partial use of horizontal wells scattered tapping the potential to further improve development results, and ultimately improve the water flooding recovery. From the point of view of many in the high water cut oilfield remaining oil development practices, tapping the potential effect of the horizontal wells is relatively good, but the high cost of horizontal wells, risk the late management and adjustments difficult, it is necessary to horizontal wells tapping program comprehensive assessment to ensure that its economic benefits. The paper, based on the use of horizontal well technology to carry out sporadic tapping the potential of this critical issue, aimed at the oilfield preferred to provide the technical and economic indicators for reference, at the same time for the oil field eventually provide important theoretical support and methods support scientific decisions. Baobei Block Baolang Oilfield this typical low porosity and low permeability reservoir study, the integrated use of reservoir description, sedimentology, reservoir geology, reservoir engineering, mechanics, petroleum economics and other disciplines theory and methods, on the basis of extensive research, combined with a lot of dynamic and static experimental data as well as previous research in the area, using the experience of analogy, reservoir engineering, numerical simulation and experimental means, by the District embark on a comprehensive evaluation of the feasibility, economy and effectiveness of the use of horizontal well technology in-depth understanding of the geological features, development characteristics and low permeability reservoir percolation characteristics, and thus the district remaining oil, sum up - sets suitable for low permeability reservoirs horizontal wells tapping the potential of the target area is preferred, and optimization of the design ideas and methods. Firstly, more comprehensive summary of the basis of the work to be completed in the use of horizontal wells in low permeability reservoirs scattered tapping the potential, namely the implementation of the tectonic and sedimentary background, grasp reservoir geological and seepage features, clear development problems, dialysis, origin and distribution of the remaining oil. Overall, the district braided river delta sedimentary system anticlinal structure on three relatively developed faults and fractures, the reservoir low porosity and permeability, strong heterogeneity, find the average starting pressure gradient for 0.0245MP / m, showing the non-Darcy flow characteristics. Numerical simulation research show that: the area of ??each monolayer remaining oil distribution quite different Ⅱ 12 Ⅱ 21, Ⅱ 22, Ⅲ 11, Ⅲ 12 single layer of remaining geological reserves are in more than 50 × 104t; imperfect well network the main influencing factors, sand The body pinches out fault cut and occlusion. Quasi-three-dimensional single-phase steady seepage single well permeability reservoir is best suited to carry out the evaluation of reservoir engineering seepage forms. On this basis, a more lucid proposed horizontal wells tapping the potential of the basic ideas of the target area preferred reservoir type preferred → development layer is preferably → horizons preferred → wellblock preferred → Productivity Evaluation → economic evaluation to determine the region's most the well area suitable arrangement of horizontal wells monolayer Ⅱ 21, the most suitable arrangement of horizontal wells B6-6 well - XZ1 well-B5-6 well-BB1205 WELL District 200m horizontal section of single well predicted capacity 8t / d or so greater than the economic limit initial capacity of 5.5t / d, and the completion of the feasibility and economic evaluation of horizontal wells tapping the potential of the program. In the preferred well area on the basis of predicted by a number of important parameters of the horizontal wells optimize the design and development indicators to complete the evaluation of the effectiveness of horizontal wells tapping the potential of the program. Optimize the location of the horizontal section from the top to portrait 1/3h, set parallel to the tectonic line; optimize the length of the horizontal section of 200m; optimize well network type irregular five spot well pattern; optimize completions way to simple perforation completion or around silk screen completion way. Numerical simulation predicted this region initial capacity of 20m3 / d, productivity index 10 m3/d/MPa, and more favorable than vertical wells. Eventually come in the area to carry out scattered tapping the potential use of horizontal well technology is feasible and economically important and effective conclusion. Innovation of the paper flow unit characteristic parameters (flow unit is an important tool for reservoir evaluation, it embodies the reservoir lithology, rock physical properties similar to the in-house, and the continuous homogeneous reservoir with vertical and horizontal) FZI values ??starting pressure gradient, the relative permeability link to expand the application fields of flow units, laid an important foundation for its development assessment and forecast. The same time, systematic summary of the ideas and methods of a design suitable for low permeability reservoirs horizontal wells, made a certain extent, an extension of the scope of optimization of horizontal wells preferably based on reservoir engineering point of view, the results obtained and the understanding of low permeability oil field using horizontal wells very important role in guiding the development of the remaining oil.