苏里格气田致密砂岩气藏差异化水平井设计方法

The Differentiation Design of Tight Sandstone Gas Reservoir Horizontal Well in Sulige Gas Field

水平井是提高致密砂岩气藏采收率的有效手段,但该类气藏具有强非均质性,砂岩多期叠置,有效砂岩零散发育,实施水平井会出现井漏、卡钻等现象,从而影响气田的产能建设,不合理的轨迹设计也会造成储量动用不充分,遗漏有效砂岩。为了避免出现以上现象,需要加强致密砂岩储层的地质研究,采用一井一设计的差异化水平井地质设计思路,从井轨迹上规避风险。收集了苏里格气田完钻井地质参数,统计了该气田的砂岩及有效砂岩钻遇情况,结合前人研究,确立了3种适合水平井开发的叠置砂体类型(块状叠置型、多层叠置型和削截式叠置型)及其有效砂体展布特征,在此基础上设计了3类水平井轨迹和节约井场的三维水平井(平直型水平井、大斜度水平井和阶梯型水平井),为气田稳产增效提供了保障。

Horizontal well is an effective method to improve the recovery of tight sandstone gas reservoirs, but this kind of gas reservoir has strong heterogeneity and sandstone folded and effective sandstone are scattered. Well leakage or sticking appears when horizontal wells construction works, and this could impair the gas field productivity. Unreasonalbe design of trajectories will cause reserves not to develop sufficient- ly. In order to avoid the above problem, we need to strengthen the geological study of tight sandstone res- ervoir, using one well with the different horizontal well design ideas, from geological design to avoid risks. This paper collects Sulige Gas Field drilling geological parameters, contain sandstone and effective sand- stone drilling parameters, combined with older studies, proposing three horizontal well development sand body stack types and effective sand body distribution characteristics. Raseon this, we design three kinds of horizontal well trajectory and 3-D horizontal wells to provide protection for the gas field production effi- ciency.