苏里格气田水平井开发技术优化

随着水平井开发规模在鄂尔多斯盆地苏里格气田的不断扩大，一些新的特殊情况又逐渐显现出来，不同程度地影响着水平井开发综合效益。为此，在前期形成的水平井配套技术的基础上，系统分析了水平井施工过程中出现的各类特殊情况和影响因素，重新对水平井选井、入靶和水平段地质导向等部分关键技术进行了优化，即：①水平井井口应选在目标层所处构造低部位，设计水平段延伸方向为沿局部砂体构造上倾的方向；②对于目标层由多个单砂体组成的砂层组，应根据实际钻遇情况灵活调整入靶位置；③水平段钻遇岩性相变，应按“先上后下”原则追踪砂层；④水平段井斜控制合理，30 m水平段井斜变化不应超过±2°；⑤水平段地质导向应以“先追踪砂体，后参考构造”为原则。现场应用结果表明，所实施水平井（包括5组丛式水平井）全获成功，完钻水平井平均砂层钻遇率达到88.2%，水平井施工单队首次实现6开6完，创下1 000 m水平段最短钻井时间（3 ｄ）记录，平均钻井周期为 48.27 ｄ。

Optimization of horizontal well development technology in the Sulige Gas Field

Along with the rapid development of the Sulige Gas Field,Ordos Basin,some special problems occurred,which has affected the comprehensive benefit of a horizontal well to some degree.In view of this,based on the existing horizontal well techniques,various special circumstances and influencing factors are systematically analyzed.Moreover,such crucial techniques as well selection,target-entering,horizontal section geosteering etc.are re-optimized.First,the well head should be positioned at a low position of the structure where the targeted stratum is located,and the direction of the horizontal section extension is just the direction of local updip structure.Second,for the targeted stratum composing of multiple single sandbodies,the location of the target-entering should be mediated flexibly according to the practical drilling situation.Third,if the lithofacies change is met at the horizontal section,a rule of first-up-then-down should be applied to track the sand bed.Fourth,the well deviation of horizontal section should be reasonably controlled and the change on the 30 m horizontal section should be within ± 2°.Fifth,the horizontal section geosteering should follow the rule of tracking the sand bed before referencing the structure.Field applications show that all the horizontal wells,including the 5 groups of cluster horizontal wells,are successfully developed.The drilling ratio of the sand bed of the drilled horizontal well reaches 88.2%.The horizontal well drilling crew has finished well service six times from spud-in to well completion for the first time,setting up a new record of 3 days as the shortest drilling time for the 1000 m horizontal section with the average drilling cycle of 48.27 days.This study provides technical support for the high-efficiency development of the Sulige Gas Field.