鄂尔多斯盆地临兴区块不同叠置模式深部煤系储层动用策略研究

Utilization strategies for deep coal-measure reservoirs with different stacking patterns in Linxing block, Ordos Basin

孙立春 刘佳 李新泽 孙乐 房茂军 李娜 樊伟鹏

SUN Lichun LIU Jia LI Xinze SUN Le FANG Maojun LI Na FAN Weipeng

中海石油(中国)有限公司 北京研究中心, 北京 100028

Beijing Research Center, CNOOC Limited, Beijing 100028, China

鄂尔多斯盆地临兴区块已进入致密气、煤层气协同开发阶段，致密砂岩与煤层的叠置模式直接影响开发方式。通过对叠置关系的研究，并从临兴区块不同开发方式生产动态出发，进行深部煤系储层动用策略研究。基于致密砂岩与煤层发育沉积特征和相对位置关系，临兴区块砂煤叠置模式主要包括砂煤互层型和上砂下煤型。对比不同叠置模式下的开发现状，水平井是深层煤层气单独开发时的首选井型，煤层气与致密气两气合采井初期产气能力高于单采煤层直井定向井。进一步建立了以经济效益为优化目标的不同叠置模式下深层煤系储层动用策略优选图版：当煤层丰度小于1.1×108 m3/km2、且致密气层为一类或二类气层时，采用两气合采方式进行开发；当煤层丰度介于(1.1~1.5)×108 m3/km2时，若致密气层不发育，采用水平井单独动用煤层，若致密气层为一类或二类气层时，则采用致密气—煤层气两气合采方式进行开发；当煤层丰度大于1.5×108 m3/km2时，若致密气层不发育或为二类、三类气层，采用水平井单独动用煤，若致密气层为一类气层，则采用致密气、煤层气单独开发方式进行开发。该研究为临兴区块及相似区块等深层煤层气资源两气协同高效开发提供技术支撑。

The Linxing block in the Ordos Basin has entered the stage of co-production of tight gas and coalbed methane (CBM), and the stacking patterns of tight sandstone and coal seams directly affect the production methods. By analyzing the stacking relationships and production dynamics using different development methods in the Linxing block, the utilization strategies for deep coal-measure reservoirs were investigated. Based on the sedimentary characteristics and relative spatial positions of tight sandstone and coal seams, the sand-coal stacking patterns in the Linxing block were mainly categorized into interbedded sand-coal type and upper sand-lower coal type. By comparing the development status under different stacking patterns, it was found that horizontal wells were preferred for the independent development of deep CBM, and wells co-producing CBM and tight gas had higher initial gas production capacity than vertical or directional wells producing CBM alone. An optimization chart of deep coal-measure reservoir utilization strategies under different stacking patterns was further established, with economic efficiency as the optimization objective. When CBM abundance is less than 1.1×108 m3/km2 and the tight gas reservoir is classified as a Class Ⅰ or Class Ⅱ, a co-production approach should be adopted. Under the condition that CBM abundance ranges from 1.1×108 to 1.5×108 m3/km2, if the tight gas reservoir is underdeveloped, horizontal wells should be used for the independent utilization of CBM; if the tight gas reservoir is classified as Class Ⅰ or Ⅱ, a co-production method should be adopted. Under the condition that CBM abundance exceeds 1.5×108 m3/km2, if the tight gas reservoir is underdeveloped or classified as Class Ⅱ or Ⅲ, horizontal wells should be used to develop the coal seams solely; if the tight gas reservoir is classified as Class Ⅰ, tight gas and CBM should be developed separately. The research provides technical support for the efficient co-production of deep CBM resources in the Linxing block and other similar blocks.

中海石油(中国)有限公司“十四五”重大科技项目课题7“临兴神府深层煤层气赋存机理及与致密气协同开发关键技术研究” KJGG-2024-1007

https://doi.org/10.11781/sysydz2025040921