特高含水砂岩油田直平组合井距优化研究

Demonstration of Straight and Horizontal Well Distance of High Water Sandstone Oilfield

哈萨克斯坦K油田储层岩性复杂,以反九点井网为主,部分反七点和四点井网组合注水开发已达37年,综合含水已达90.5%。为了充分挖潜、提高储量动用程度,探索通过直井注水、水平井采油的直平组合开发方式动用剩余油。应用地质、测井、油藏工程等多学科理论,结合数值模拟结果,论证不同平面位置组合、不同井距条件下储量动用效果。直平组合注采井距和油层厚度、注水井位置等关系较大,最小井距不小于200 m,最大井距为油田标定采收率设计的注采井距。通过进一步论证设计,在K油田部署实施水平井38口。平均单井初期日产油17.9 t,含水68.7%,充分证实应用水平井技术,通过直平组合进行高效开发高含水砂岩油田、动用剩余油的可行性。

The K oilfield of Kazakhstan has complex reservoir lithology and high heterogeneous interlayer. It was mainly developed by inverted nine-spot pattern,partially developed by inverted sevenspot and combination with four wells by water flooding for 37 years,and the comprehensive water content is 90. 5%. In order to dig the potential remaining oil and improve the degree of producing reserves,we explored the way of combination of water injection to straight direct well and oil production by horizontal well in developing the remaining oil. Then we took the application of geology,logging,reservoir engineering and many multidisciplinary theories,combined with the results of numerical simulation,then we demonstrated the percentage of producing reserve in different plane position combination and different distance of wells. The well spacing of the combination of straight and horizontal wells has large relationship with the thickness of reservoir and the location of the injector. The minimum well spacing need to be no less than 200 meters and the maximum well spacing is designed by the demarcate recovery ratio of the oilfield. It has already deployed 38 horizontal wells in the K oilfield by further argument. The average daily oil production of single well has reached 17. 9 t/d and the water content was 68. 7%. It has been proved that it is feasible to use the horizontal well and combination with straight and horizontal well in efficient development of high water content sandstone oilfield and feasible to produce the remaining oil.