纯41断块沙四段现今地应力场有限元模拟

梁家楼油田纯41断块位于东营凹陷的西南部，主要油气产层是沙四段。现今地应力对油田开发有重要影响。用岩心声速法和井斜统计法确定关键井的水平主应力方向，用声发射法测量关键井的水平最大主应力，用水力压裂法计算关键井的水平最小主应力。以关键井的地应力测量、计算结果为约束条件，采用弹性平面有限元法模拟该断块沙四段现今地应力场，结果是：水平最大主应力值为52—74MPa，断块内部为近东西向，断层带主要为北西向；水平最小主应力值为41—52MPa，断块内部为近南北向，断层带主要为北东向。图5表3参10

Finite element simulation of the present ground stress field of Sha-4 Member in the Chun-41 fault block

Chun 41 fault block of the Liangjialou oil field, whose main oil and gas producing intervals are Sha 4 member, is located in the southwest of the Dongying Sag. The present ground stress has important effect in the exploitation of oil field. The horizontal principal stress orientations were established by core acoustic velocity and well drift statistics; the maximal horizontal principal stresses were measured by acoustic emission and the minimal horizontal principal stresses of key wells were calculated by hydraulic fracturing. Taking ground stress results of key wells as constraint condition, the present ground stress field of Sha 4 member is simulated with elastic plane finite element in this fault block. The results are as follows: the maximal horizontal principal stress is 52 74MPa, and the direction is close to east west within the fault block and mainly northwest within the faulted zone; minimal horizontal principal stress is 41 52MPa, and the direction is close to south north in this fault block and mainly northeast within the faulted zone.