喇嘛甸油田钻井地质风险识别及设计对策

Risk Identification and Countermeasures of Drilling Geology in Lamadian Oilfield

喇嘛甸油田钻井中的地质风险分为地层异常高压、浅层气及气顶气发育、嫩二段及油层套损、井壁坍塌以及浅层套管腐蚀等5大类。这些风险导致钻井中时常出现油气侵、井涌以及井壁坍塌等复杂情况,部分油水井生产中油层套管损坏,浅层套管腐蚀。这些增加了钻井及生产成本。根据设计井与周围油水井和断层的位置关系,结合注采情况,识别出由于受断层遮挡、油层注采不平衡、注水井套损等因素引起的地层异常高压区;利用钻井录井中的油气显示,结合测井曲线划分浅层气以及气顶气区。针对存在的地质风险,提出了钻井地质设计中需采取的措施,为进一步指导钻井设计和施工风险控制提供了依据。

Drilling geological risks of Lamadian Oilfield included five types:abnormal high formation pressure,the development of shallow gas layer and gas cap gas,casing damage in the second member of Nenjiang Formation and in the oil reservoir,borehole sloughing and casing corrosion in the shallow layers.Some complicated conditions in drilling including invasion of oil and gas,well kick and borehole sloughing were frequently caused by these risks,casing damage in the reservoir and casing corrosion in shallow layer were induced in part of production wells,by which the drilling and production cost were raised.According to the positions of designed wells with the adjacent wells and the faults,combined with the injection and production condition,the region of abnormal high formation pressure was recognized which was caused by fault barrier,unbalance of injection and production,casing damage of injection well and other factors.The shallow gas layer and gas cap gas region are divided by using oil and gas show in drilling and the logging curves.Aiming at the geological risks,this article puts forward the measures for the drilling geological designs,which provide a further guidance for drilling designs,it provides a basis risk control in drilling design and operation.