渤海油田复合储集层水平段钻遇率的提高方法与应用效果

Improvement methods and application effects of the rate of drilling composite reservoir horizontal section in Bohai Oilfield

渤海油田X区块为半背斜层状油气藏,目的层为河流相沉积储集层,非均质性强,储集层预测难度大,采用同一水平段钻穿多层砂体联合开发的方式,导致水平段钻遇泥岩的情况不可避免。长期以来X区块水平段钻遇的大段泥岩给钻井施工带来困难,造成调整缺乏方向性,储集层钻遇率偏低。为解决这一问题,依据X区块Ⅰ期已钻13口井钻探资料分析归纳每口井着陆、完钻特点,应用地质模型和预测公式,对Ⅱ期开发井着陆、完钻位置给出建议。该研究成果在X区块水平井实施过程中取得良好的效果,提高了储集层钻遇率,为应用水平井开发层状构造油气藏提供了有益的借鉴。

X block in Bohai Oilfield is a semi-anticline stratified hydrocarbon reservoir,target stratum is a fluvial facies sedimentary reservoir with strong heterogeneity,and reservoir prediction is difficult.Using the same horizontal section to drill through multi-layer sand bodies,it is inevitable to drill mudstone in horizontal section.For a long time,large segment of mudstone encountered in the horizontal section of X block has caused difficulties in drilling construction,resulting in lack of directional adjustment and low reservoir-encountered rates.To solve this problem,according to drilling data of 13 wells drilled in stageⅠof X block,the landing and completion characteristics of each well were analyzed and summarized.Based on geologic model and prediction formula,suggestions for landing and the position of accomplishment of drilling of stage Ⅱdevelopment well were given.The study has achieved good results in the implementation of horizontal well in X block,improved the rate of drilling reservoir,and provided a useful reference for the application of horizontal wells to develop layered structure oil and gas reservoirs.