高级检索

高煤阶煤层气水平井和直井耦合降压开发技术研究

Study on technology of horizontal wells and vertical wells coupled depressurization in high rank coalbed methane

  • 摘要: 高煤阶煤层气低产低效区的普遍存在,已成为制约我国煤层气产业发展的主要瓶颈之一,为此,以山西沁水盆地郑庄区块开发为例,通过综合运用动态分析和数值模拟技术,对合理的开发技术进行了研究。针对该区块井距偏大,单井实际动用储量低,不能实现井间协同降压导致低产的问题,利用水平井开发煤层气的技术优势,创新地提出了水平井耦合降压盘活直井技术,通过分支井眼与直井压裂裂缝的相互交错串接,使煤储层裂隙间畅通,大幅提高了裂隙的导流能力,实现水平井和直井井间耦合降压,盘活低效区。研究结果表明:该技术在郑庄区块试验取得了显著的开发效果,4口加密水平井平均单井日产气4 849 m3/d,产气量稳定,盘活邻井平均单井日增气量580 m3/d,提高了区域的储量动用程度和采出程度,因此建议在高煤阶煤层气低效区块广泛推广,可以有效提高地质储量的采出程度,整体盘活低效老井。

     

    Abstract: Low production and low efficiency area in high rank coalbed methane widely exist, which has already become one of the main bottlenecks in restricting the development of coalbed methane industry in China.In this study,the development of Zhengzhuang Block in Qinshui Basin of Shanxi Province was taken as an example.The reasonable development technology policy was studied using dynamic analysis and numerical simulation techniques. In view of the fact that the well spacing in this area was too large and the actual utilization of individual well was low, it was impossible to solve the problem of low production due to cooperative pressure reduction between wells.Utilizing the technical advantages of horizontal wells to develop CBM, the horizontal well- vertical well coupling pressure reducing activation technology was proposed innovatively. By interleaving series of cross-boreholes with vertical well fracturing cracks, the fractures in the coal seam were connected, largely improving the fracture diversion capability, and realizing coupling of the pressure between horizontal and vertical wells. Then the low-production vertical wells were revitalized.Research shows that this technology has acquired significant achievements in the Zhengzhuang Block. The average production of four infilled horizontal wells is 4 849 m3/d with stable production. Besides, adjacent vertical wells are activated. The average increasing production is 580 m3/d.The reserve productivity and recovery degree of the block are improved effectively.It is recommended to use this technology in the low production and low efficiency areas in high rank coalbed methane wells, which can effectively improve the recovery degree of geological reserves and activate inefficient old wells.

     

/

返回文章
返回