渤海海域JZ25—1S潜山裂缝型油藏具有非均质性强、空间结构复杂及裂缝倾角较大等特点,开发存在巨大困难。以油藏数值模拟为手段,建立了机理模型,对影响潜山裂缝型油藏开发的关键因素进行了研究,同时对水平井开发井网关键参数进行了定量分析。研究结果表明:JZ25—1s裂缝型油藏最优的井网形式为水平井顶底平行交错立体井网,水平井与主裂缝方向呈45。夹角、无因次避水高度为0.85、最优井距为650m左右、最优水平井长度为800m;油藏生产压差的最优值为0.6MPa,前5年的采油速度为3%左右,前10年的采油速度为2%左右。通过以上成果的应用,该油藏初期产能达到了600~1500m3/d,阶段开发效果较国内同类型油田要好,实现了海上复杂岩性油藏的高效开发。
JZ25-1S buried hill fractured reservoir is a typical complex lithology reservoir in Bohai sea, which has strong heterogeneity, complicated space structure, large fracture dip, making its development ex- tremely difficult. Based on the establishment of the mechanism model, the key factors affecting the devel- opment of buried hill reservoirs and the key parameters of horizontal well pattern were studied with the reservoir numerical simulation. The results show that the optimal well pattern for JZ25-1S fractured reser- voir is three-dimensional well pattern that is staggered by top and bottom horizontal wells. The key param- eters in horizontal well development are as follows: the angle between the horizontal wellbore and the main fracture direction is 45~~ the dimensionless water avoiding height is 0.85~ the optimal spacing for horizon- tal wells is about 650 m; the optimal length is 800 m~ the optimal production drawdown is 0.6 MPa; and the production rates in the first five and 10 years are about 3.0% and about 2% respectively. By applying the key research findings, the single well deliverability reached 600 to 1 500 m3/d, indicating that the de- velopment effeet was much better than domestic similar oilfields, and the goal of efficient development for offshore complex lithology reservoirs has been achieved.