全可溶变径球座体积压裂工具研制与应用  

Development and Application Of Fully Soluble Variable Diameter Ball Seat Used for Volume Fracturing

作　　者：郭思文 王治国[1,2] 薛晓伟 赵敏琦[1,2] 李治君 张家志[3] 任国富 费二战[4] GUO Siwen;WANG Zhiguo;XUE Xiaowei;ZHAO Minqi;LI Zhijun;ZHANG Jiazhi;REN Guofu;FEI Erzhan(Oil&Gas Technology Research Institute of Changqing Oilfield Company,XI’an,Shanxi 710018,China;National Engineering Laboratory for Permeability Oiland Gas Field,Xi’an,Shanxi 710018,China;No.4.Gas Production Plant of Changqing Oilfield Company,Xi’an,Shanxi 710000,China;No.3 Oil Production Plant of Changqing Oilfield Company,Xi’an,Shanxi 710000,China)

机构地区：[1]中石油长庆油田分公司油气工艺研究院 [2]低渗透油气田勘探开发国家工程实验室 [3]中石油长庆油田分公司第四采气厂 [4]中石油长庆油田分公司第三采油厂

出　　处：《钻采工艺》2020年第5期75-77,I0005,共4页Drilling & Production Technology

基　　金：中国石油集团公司科技项目“油气藏储层改造技术持续攻关专项”(编号:2014FCCYLGZ001)。

摘　　要：长庆油田致密油气藏水平井主要采用快钻桥塞和可溶桥塞进行改造,随着水平段长度的增加,施工中出现以下问题:快钻桥塞在长水平段钻磨时钻压难以施加;可溶桥塞橡胶件溶解时间较长易形成残留物堵塞井筒。针对这一问题,开展了全可溶变径球座的研制,设计了带导轨的四瓣式结构,入井时分瓣相互错开,球座处于缩径状态,下到预定位置后,分瓣闭合形成球座,处于扩径状态,实现段间封隔,并调整了可溶材料配方,使球座可产生微塑性形变增加了金属密封可靠性,压后全部溶解实现免钻磨。室内评价结果表明,球座丢手顺利、坐封可靠、承压达到70 MPa、在50℃返排液条件下120 h可全部溶解。现场开展了6口井的试验,封隔可靠、压后免钻、全通径、综合成本低,能够满足致密油气藏长水平段水平井密切割体积压裂要求。For the horizontal wells of tight oil and gas reservoirs in Changqing oilfield,fast drilling bridge plug and imported soluble bridge plug are mainly used for volume-fracturing stimulation. With the increase of the length of the horizontal section,the following problems occur in the fracturing: It takes longer time for rubber section of soluble bridge plug to dissolve thoroughly,which result in forming residue and blocking the wellbore passage. In order to solve this problem,Oil & Gas Technology Research Institute of Changqing Oilfield Company carries out the research of variable diameter ball seat that can be totally dissolved. The structure of the variable diameter ball seat is made of four petals with track. During string running,four petals are separated and the diameter of ball seat is minimum.When the string reaches the desired location,four petals are closed forming the whole ball seat and the diameter of ball seat is maximum,which can realize the obstruct between the fracturing stage. By adjusting the content of Sc in the soluble material formula,the ball seat can produce micro plastic deformation,which can increase the reliability of metal sealing. After fracturing,ball seat can be fully dissolved with no need for drilling and grinding. Laboratory evaluation shows that the ball seat can reliably be set between the fracturing stage,bearing the pressure of 70 MPa and was dissolved after 120 hours under the condition of 50 ℃ flowback fluid. The field test of 6 wells shows that the isolation between the stages is reliable,free of drill grinding operation and full bore is realized after fracturing. Compared with imported soluble bridge plug,tool cost of fully soluble variable diameter ball seat is reduced by 40 percent,which can meet the requirements of tight volume fracturing of horizontal Wells in the long horizontal section of tight oil and gas reservoirs. In order to improve the success rate of ball seat operation,it is suggested that double well volume liquids should be used to replaced the sand-carryin

关 键 词：长水平段水平井 全可溶 变径球座 金属密封 免钻磨 

分 类 号：TE934.2[石油与天然气工程—石油机械设备]