摘要
在石油钻井施工过程中若钻遇岩层构造裂缝,往往会导致不同程度的钻井液漏失。由于地层裂缝发育的非均质性特点,钻井施工现场尚无有效方法对裂缝发育情况进行预判,需在钻井井漏发生以后再采取堵漏措施,不仅造成了施工成本的增加还造成了钻井周期的延长。为此,提出一种用主曲率法预测因裂缝导致井漏的方法,将岩层视为一个几何实体,采用趋势面方法建立区域岩层构造模型,运用微分几何中的主曲率法来刻画岩层弯曲变形程度,以实钻井情况作为约束条件确定井漏的主曲率范围,从而以主曲率场的分布特征来指示构造裂缝发育区带,达到预测井漏的目的。该方法在西北油田顺北区块钻井现场进行了应用,结果表明主曲率法能有效预测井漏并指导钻井现场进行安全、高效地施工。
In the process of petroleum drilling construction,the drilling fluid leakage will be caused to different degrees if the drilling meets the structural fracture of rock formation.Due to the heterogeneity of formation fracture development,there is no effective method to prejudge the fracture development in drilling site,it is necessary to take plugging measures after drilling well leakage,which not only increases the construction cost but also prolongs the drilling cycle.Therefore,a principal curvature method of predicting lost circulation caused by fractures is proposed.The rock formation is regarded as a geometric entity and the regional rock formation structural model is established by using the trend surface method.The bending deformation degree of the rock formation is characterized by the principal curvature method in differential geometry.The principal curvature range of the lost circulation is determined with the actual drilling condition as the constraining condition,so that the distribution characteristics of the principal curvature field can be used to indicate the structural fracture development zone,so as to achieve the purpose of predicting the lost circulation.This method has been applied to the drilling site of Shunbei block in Northwest Oilfield.The results show that the principal curvature method can effectively predict the lost circulation and guide the drilling site to carry out the safety and high efficiency construction.
作者
卢世浩
杨红满
胡江涛
Lu Shihao;Yang Hongman;Hu Jiangtao(Front Command Base,Northwest Oilfield Company,Luntai County,Bazhou,Xinjiang,841600,China)
出处
《录井工程》
2019年第4期17-21,145,146,共7页
Mud Logging Engineering
关键词
顺北区块
主曲率法
裂缝
井漏
预测
Shunbei block
principal curvature method
fracture
lost circulation
prediction
