摘要
采用ADS法对塔里木某地区深层致密砂岩储层的地应力进行计算研究。首先在区分砂、泥岩前提下提取纵横波时差转换关系，然后采用声发射（AE）和压裂（HPF）资料标定水平主应力求得水平骨架非平衡因子μg，μg有随着深度增加而减小的趋势，最终获得水平最大和最小主应力计算模型及志留系致密砂岩储层三大主应力连续剖面，地应力满足σv＞σH＞σh的关系，为正常应力系统。最后对地应力、破裂压力、地层压力和坍塌压力对合理钻井液密度窗的影响和计算方法进行了分析，建立了三压力剖面，确定了钻井液安全密度窗。实际采用1.34～1.4 g/cm^3钻井液密度可确保井下正常，与计算的安全窗范围相一致。
ADS method was used to calculate geo pressure in deep and tight sandstone reservoirs in one area of Tarim Basin. An alteration of both P- and S-wave moveout was extracted after sandstone and mudstone division. Horizontal principal-stress was calibrated by adopting acoustic emission(AF) and fracturing data. After that, a non-balance factor ofμg, decreasing with depth increase, was obtained. At last, some calculation models of horizontal maximum and minimum principal-stress as well as three principal-stress continuous sections of Silurian tight sandstone reservoirs were gained; and that geo stress satisfies with σv>σmax>σminis a normal pressure system. In addition, the effect of geo stress, breakdown pressure,formation pressure and collapse pressure on reasonable drillingfluid density window and the ADS method were analyzed; a threepressure section was developed; and a safety density window was determined. Actually, the drilling-fluid density ranging from1.34~1.4 g/cm3, which is consistent with the calculated one, can guarantee a normal downhole operation,
出处
《天然气技术与经济》
2014年第4期21-24,78,共4页
Natural Gas Technology and Economy
关键词
深层
致密砂岩
地应力大小
ADS法
钻井液密度窗
deep zone,tight sandstone,geo stress,ADS method,density window of drilling fluid
