Shanxi Lanyan Coalbed Methane Engineering Research Co., Ltd.

郑庄区块位于沁水盆地西南部,主产气层位为山西组 3 号煤和太原组 15 号煤,区内煤层赋存特征以及含气性无论从垂向上还是横向上均差异较大。分别对 3 号煤和 15 号煤的主裂缝延伸方向以及含气性进行分析,在此基础上对该地层水平井钻井体系进行了优化,结果显示:3 号煤的水平最大主应力方向应为北东 45°~60°,南西 225°~240°;15 号煤的水平最大主应力方向应为北东60°~75°,南西 240°~255°。15 号煤水平最大主应力方向与 3 号煤的相差 15°左右。3 号煤层属特低硫~低硫无烟煤,煤厚基本在 5~6 m。15 号煤层属中高硫~高硫无烟煤,煤层厚度在横向上总体较稳定,一般为 4~5 m,煤层结构较为复杂。3 号煤层和 15 号煤层含气量由区块南部向北部略有增加的趋势,呈现北东向展布的相对富集区夹小面积零星分布的相对低含气量区。优化钻井体系主要从钻井设计方案优化和钻井过程优化两个方面来实施。钻井设计方案优化主要包括:钻井设计理念的优化、井位优化和钻井轨迹设计优化。钻井过程优化主要包括:钻井设备优化、钻井液体系优化和井眼轨迹控制。井眼轨迹控制包括:无导眼精准着陆、弯曲段井眼轨迹控制、着陆时井眼轨迹控制和着陆后水平段井眼轨迹控制。ZH-L36 井运用优化后的钻井体系,最终煤层钻遇率达到 99%,压裂后产气量达 4 万 m3/d。区块运用优化后的钻井体系,日产气量提高了 100 万 m3/d。

Zhengzhuang block is located in the southwest of Qinshui Basin. The main gas producing horizons are No.3 coal of ShanxiFormation and No.15 coal of Taiyuan formation. The occurrence characteristics and gas bearing properties of coal seams in the area arequite different both vertically and horizontally. In this study, the main fracture extension direction and gas content of No.3 coal and No.15coal were analyzed respectively. On this basis, the horizontal well drilling system in this formation was optimized. The results showed:The maximum horizontal principal stress direction of No.3 coal seam should be NE 45°−60°, SW 225°−240°. The maximum horizontalprincipal stress direction of No.15 coal seam should be NE 60°−75°, SW 240°−255°。The difference of maximum horizontal principalstress direction between No.15 coal and No.3 coal is 15°. No.3 coal seam belongs to extra low sulfur - low sulfur anthracite, the thicknessof coal is 5−6 m. No.15 coal seam belongs to medium high sulfur high sulfur anthracite, The thickness of coal seam is generally stable horizontally, generally 4−5 m, The structure of coal seam is complex. The gas content of No.3 coal seam and No.15 coal seam increasesslightly from the south to the north of the block,there are relatively rich areas with Northeast Distribution and relatively low gas contentareas with small area scattered distribution. The optimization of drilling system was mainly implemented from two aspects: drilling designoptimization and drilling process optimization. The optimization of drilling design mainly included: the optimization of drilling designconcept, well location and drilling trajectory. The optimization of drilling process mainly included: drilling equipment optimization,drilling fluid system optimization and well trajectory control. Well trajectory control includes precise landing without pilot hole, well trajectory control in curved section, well trajectory control during landing and well trajectory control in horizontal section after landing. Theoptimized drilling system was used in well zh-l36, and the drilling rate of coal seam reached 99% and the gas production after fracturingreached 40 000 m3/d. By using the optimized drilling system, the daily gas production increased by 100 m3/d.

国家自然科学基金资助项目(U1810201);晋城市重点研发计划资助项目(20210212)

李贵山, 于振锋, 杨晋东, 等. 沁水盆地郑庄区块煤层气水平井钻井体系优化[J]. 煤炭科学技术, 2023, 51(4): 118-126.

LI Guishan, YU Zhenfeng, YANG Jindong. Optimization of drilling system for CBM horizontal wells in Zhengzhuang Block of QinshuiBasin[J]. Coal Science and Technology, 2023, 51(4): 118-126.