Research and Field Application of Top Screen Cementing Technology with the Salvaging Type Plug-Drilling-Free Tool

Top screen pipe cementing technology of casing in horizontal well has been one of the main completion, especially for developing reservoirs with bottom and edge water and heavy oil reservoirs. Main drawbacks of screen top cementing completion technology in horizontal wells are casing wear in the process of drilling plug and burrs in the inner surface after drilling plug which are obstacles of well intervention. The salvaging type Non-plug-drilling tool eliminates the disadvantages of plug-drilling. By optimizing tool structure, improving technology, the reliability of salvaging type plug-drilling-free tool has been increased. More than 133 wells in 2012 had adopted the salvaging type plug-drilling-free tool with high reliability in Pai 601 Block of Xinjiang with 100% success rate.  Key words: Horizontal well; The salvaging type plug-drilling-free technology; Completion; Top screen cementing technology; Field applicatio

Least Squares Based Iterative Algorithm for the Coupled Sylvester Matrix Equations

By analyzing the eigenvalues of the related matrices, the convergence analysis of the least squares based iteration is given for solving the coupled Sylvester equations AX+YB=C and DX+YE=F in this paper. The analysis shows that the optimal convergence factor of this iterative algorithm is 1. In addition, the proposed iterative algorithm can solve the generalized Sylvester equation AXB+CXD=F. The analysis demonstrates that if the matrix equation has a unique solution then the least squares based iterative solution converges to the exact solution for any initial values. A numerical example illustrates the effectiveness of the proposed algorithm