纤维复合无筛管防细粉砂技术在涩北气田的应用

Application of the screenless fine silty sand controlling technology of fiber-resin sand complex in the Sebei gas reservoir,Qaidam Basin

柴达木盆地涩北气田是中国第四大气田,其储集层为第四系粉砂岩和泥质粉砂岩,胶结疏松,出砂严重,常规防砂技术基本无效或效果很差。根据对该气田储集层的研究,其防砂作业要采用软纤维稳砂预处理技术和处理液(处理液由可防止储集层岩石润湿反转的表面活性剂和可以稳定细粉砂颗粒的软纤维稳砂剂组成)。基于对具有防砂效能的纤维与涂层砂形成的三维网状复合体结构与性能的研究,研制出在储集层条件下稳定并能抗温、抗酸、抗碱和抗地层水侵蚀的防砂专用特种纤维复合体,用盐湖水配制出低损害清洁压裂液,并设计了压裂端部脱砂与控制工艺,形成了纤维复合体技术、清洁压裂液技术和端部脱砂技术集成配套的纤维复合无筛管防细粉砂技术。用该技术在涩北气田12口井进行先导试验,取得了显著的防砂效果,防砂后的不出砂产气量是防砂前产气量的1.75倍以上。

.Sebei gas field in the Qaidam Basin is the fourth largest gas field of China. Its main pay-zone is unconsolidated Quaternary fine siltstone and pelitic siltstone with serious sand production, where the conventional sand-control methods are of no effect. According to the study of the Sebei reservoir, it was considered that the formation pretreatment technique to stabilize fine siltstones with soft fiber should be used in the sand control system. The formation pretreatment fluid is made up of surfactant that can prevent rock wettability reverse and soft fiber to stablilize the fine grains. Based on the study of the framework and performance of the 3-D sand controlling complex composed of fiber and resin-coated sand,a special fiberand resin-coated sand complex, which has good stability under reservoir conditions and has capabilities against high temperature, acid, alkali and formation water corrosion, was developed. Clear fracturing fluid that can protect reservoir was prepared by using brine water, and TSO （tip screen out） fracturing and sand control technique was elaborately designed. Finally an integrated screenless fine-sand-controlling technology of fiber-resin sand complex was developed, which includes fiber-complex technique, clear fracturing fluid technique and TSO technique. The technology was applied to 12 wells in the Sebei gas field and good results were gained in sand control. After the sand control treatment, sand production stopped and the gas production rate was up to more than 1.75 times.