潘庄区块煤层气U型水平井下套管技术探讨

下入生产套管的煤层气U型井具有产气量高、成本低的优点，逐渐成为潘庄区块煤层气开发的主要井型。潘庄区块煤层埋深一般在500 m以浅，同时要求U型井的水平段在1000 m左右，生产套管的下入成为该区块垂深浅、水平段长的煤层气U型井的技术难题，经过多口井试验，优化钻井轨迹的平滑度，采用原钻具、短螺旋扶正器和生产套管内置钻铤3次划眼，以及严格控制下套管程序，可提高套管一次性下入的成功率，并提高生产效率。

Discussion on the Downhole Casing Technology for U Shape CBM Wells of Panzhuang Block

Because of the advantages of high gas production and low cost,U-shaped CBM well with production casing has gradually become main well type. The buried depth of coalbed is generally less than 500m in Panzhuang block and the horizontal section for U-shaped well is required to be about 1000m. For the shallow vertical depth and long horizontal section, production casing running is a technical difficulty in U-shaped CBM well of this block. In the tests in several wells, by optimization of drilling trajectory smoothness, 3 times of sweeping with original drilling tools, short spiral centralizer and drill collar in production casing as well as strict control on casing lowering program, the success rate of one-time casing lowering can be increased with higher production efficiency.