沁南某高阶煤井区煤层气井气、水产出差异及其控制因素

李 超，申 建，赵锦程，杨春莉

(1.中国矿业大学，江苏 徐州 221116；2.中国石油天然气股份有限公司华北油田分公司，河北 任丘 062552)

Control mechanisms of water production and gas production divergences ofCBM wells in southern Qinshui basin

LI Chao1，SHEN Jian1，ZHAO Jincheng1，YANG Chunli2

(1.China University of Mining and Technology,Xuzhou 221116，China；2.PetroChina Huabei Oilfield Company,Renqiu 062552，China)

Recognizing the major controlling factors of water production and gas production divergences between CBM wells can promote the benefits in the process of CBM development.The divergences of water and gas production between CBM wells were analyzed,and then the geological control mechanisms of those divergences were further discussed,based on the dynamic data of exploration and development collected from 144 wells drilled in a high-rank coalbed methane well area in the south part of Qinshui basin.The results show that,various water wells and gas wells are belts distributed on the plane in the study area,showing the characteristics of high water yield and low gas production.Moreover,the production of CBM wells is mainly controlled by groundwater and tectonic styles,which is mainly reflected in two aspects.First,the water source of CBM wells mainly comes from fracturing water,coal seam water and surrounding rock make-up water which is mainly derived from adjacent sandstone.Second,the high-productivity wells in the study area are usually distributed over the wings of the sublevel anticline on axis and the wings of local synclinorium;the medium-productivity wells predominantly distributed over local synclinoria relief wing and secondary syncline wings;besides the low-productivity wells are primarily distributed over the axis of the secondary syncline and the high point of structures in the eastern part of the study area.Finally,it is suggested that the scale of fracturing should be controlled in well areas with high water productivity and the long term effective operation of the pump should also be guaranteed.However the scale of fracturing in well areas with low water productivity should be increased,and special attention should be paid to the control of early groundwater production.

Qinshui basin;coalbed methane(CBM);daily gas production;daily water production;groundwater

煤储层流体系统包含气、水两大要素，二者长期共存，彼此影响[1]。因煤层气独特的吸附态赋存特征，主要通过排水来降低储层内流体压力，继而使煤层气由吸附态转为游离态而产出[2]。煤层气井排采实践表明：煤层气井的产水、产气差异显著，且高产水往往不利于培育高产气井[3-4]。究其原因，学者提出了煤层非均质性、强储层敏感性、煤体结构、含气量、构造与水文地质等差异控制学说[5-8]。然而，受潜在影响因素众多、各因素实测数据数量和质量局限且对其参数相关关系少有阐述等影响[9-11]，煤层气井气、水产出关键控制因素尚未有统一、可靠和简练的认识。沁水盆地是我国高阶煤煤层气开发最为成功的地区，作为最早投入生产的南部某井区，区内煤层气井储层参数较为完备且已有超过10年的排采历史，基本可以代表煤层气井生产的全周期。因此，本次研究拟通过深入解剖该井区煤层气井的气、水产出差异性及其控制因素，基于参数相近特点排除部分储层因素，着重查明构造和地下水条件对其控制，以期为相似区煤层气井高效开发工程选择提供参考。

2017-10-12 责任编辑：刘艳敏

国家科技重大专项资助(编号：2016ZX05041001-002)；国家自然科学基金项目资助(编号：41672149)

李超(1993-)，男，安徽滁州人，硕士研究生，E-mail：lmc937615@163.com。

李超，申建，赵锦程，等.沁南某高阶煤井区煤层气井气、水产出……