地层漂移在青西地区井位部署上的应用

Application of Stratum-drift in Well Location Deployment in Qixi

在玉门油田青西地区的钻井过程中发现,白垩系地层漂移,同时自然造斜也很严重,井身质量控制难度很大。为了解决这一问题,经过对青西地区完钻井井底闭合方位的研究,发现白垩系地层漂移有一定的规律可循,并将这一地层漂移规律用来部署井位,即通过确定一个方位角提前量和水平位移,由此来确定井口的位置。这种方法在两口井上得到应用,实践表明,这两口井的机械钻速比没有应用这一规律的直井和定向井都有所提高,钻井周期相应缩短。利用这种方式确定井位,既可以减少直井在易斜地层防斜打直的工作,同时还可以降低定向井轨迹控制的难度,提高了机械钻速,缩短了钻井时间,为解决地层漂移和自然造斜严重地区井身质量难以控制的问题,提供了一个思路。

During the drilling in Qinxi in Yumen oilfield, it is found that Cretaceous stratum drifts, natural inclination is serious, and controlling the quality of well bore is very difficult. In order to solve the problems, the study on closure azimuth of finishing drilling wells in Qinxi shows Cretaceous stratum drift has some tendency. Using the tendency can deploy the well location, namely, the well location can be designed by the determination of an advance azimuth angle and horizontal displacement. The method has been used in two wells. The results show that the penetration rate of the two wells is higher than that of vertical well and directional well which didnt adopt the tendency and the drilling cycle is shorter. Using this way to determine the well location can avoid protecting normal drilling against tilting in easily - tilting stratum, reduce the difficulty of trajectory control of directional well, improve the penetration rate, and reduce drilling time. It provides a new way for tackling the difficulty on how to control the well bore quality in stratum drift and serious natural inclination area.