分体式自适应分支井主井眼支撑系统研制

Development on Split Adaptive Support System for Main Hole of Multilateral Wells

分支井主井眼支撑工具是满足分支井窗口支撑与分支井眼钻井的核心工具,包括可回收式斜向器、打捞钩、定向锚定封隔器及定向插头等。针对常用配套工具存在的锚定性能差、地面定向难度大、斜向器可取性差等问题,研发了分体式自适应分支井主井眼支撑系统。该系统以大通径锚定封隔器作为井下定位单元,具备轴向及周向锚定功能,可取式钻井导向器可在井下实现自动找正对接,从而建立牢固的窗口支撑系统,配套打捞钩具备定向打捞功能;该系统也可为后期井眼选择性重入及生产提供大通径机械通道。对主井眼窗口支撑系统关键部件进行了有限元分析,并对支撑系统的锚定、抗扭及自动对接等性能进行了测试。分析及测试结果表明:大通径锚定封隔器双向锚定能力1200 kN,环空封隔能力80 MPa;钩式打捞器可实现导向器的定向锁定。所得结果可为分支井设计及工具选择提供参考。

The support tool for the main hole of a multilateral well is the core tool realizing multilateral well window support and drilling branch holes,including retrievable whipstock,fishing hook,directional anchor packer and directional plug.In order to solve the problems of commonly used support tools such as poor anchoring performance,great difficulty in surface orientation and poor retrievable property of whipstock,a split adaptive support system for main hole of multilateral well was developed.This system uses a large-diameter anchor packer having axial and circumferential anchoring functions as the downhole positioning unit;the removable drilling guide can realize self-alignment and abutting in the well,thus building a reliable window support system;the matched fishing hook possesses directional fishing function;this system can also provide a large-diameter mechanical channel for selective reentry and production of the well in the later stage.Then,finite element analysis was conducted on the key components of the main hole window support system,and the anchoring,torsional and automatic abutting performances of the support system were tested.The analysis and test results show that the two-way anchoring capacity and annular sealing ability of the large-diameter anchor packer is 1200 kN and 80 MPa respectively,and the hook fisher can achieve directional locking of the guide.The research results provide reference for the design of multilateral wells and selection of tools.