煤层群发育区煤层气开发模式的地质选择机制

Geological selection is the foundation of coalbed methane(CBM) development model for reasonable determination. The formation of coalbed methane reservoirs is particular in condition of multi-coalbeds, and its properties determined the complexity of geological selection of CBM development mode. The paper puts forward some scientific problems which are reservoir forming of CBM in multi-coalbed zones and suitability of development technology of CBM. Using the method of geological analysis and taking the Zhina and Pajiang mining area in western Guizhou, as a case, the development geological characteristics and the formation of CBM reservoirs would be discussed based on new ideas and methods, such as multi-scale model superposition, induced energy and transfer in coal seams. The characteristic methods of development geological conditions in multi-coalbeds zones, suitability of geological conditions and development mode, matching method and mechanism would be discussed, to found particularity of CBM reservoir forming and geological characteristics of CBM development; to clear the mapping relationship and matching degree of development geological type formed by matched geological modes and CBM development mode reconstructed, and considering the target zone as an object, the applicants attempt to obtain preliminarily the possibility of coal series gas co-exploration, adaptive development geological conditions, development geogogical type, technology ways and what mode the technology belongs where, to illuminate initially geological selection mechanism and selection method of CBM development mode in multi-coalbeds zones, and to answer the question on validation and suitability of CBM development engineering from the model level. Consequently, the research will provide geological theoretical evidence for multi-coalbeds zones to choose the CBM development technology and mode.

地质选择是合理确定煤层气开发模式的根本依据，煤层群煤层气成藏特殊性决定了煤层气开发模式的地质选择更具复杂性。由此提出的关键科学问题是煤层群发育区煤层气成藏特殊性及其开发工艺技术适配性问题。以煤层气资源丰富且煤层群发育的黔西织纳矿区和盘江矿区为工区，采用多尺度模型叠加、能量诱导转移等新的思路与方法，探讨煤层群发育区煤层气开发地质条件的表征方法、开发地质条件与开发模式的适配性、匹配方法与机制，揭示煤层群煤层气成藏特殊性与煤层气开发地质基本特点，明确模型组合搭配形成的开发地质类型与重建开发模式的映射关系和匹配程度，初步论证以目标层段为对象的煤系地层非常规气共采可能性、适配开发地质条件/类型、技术途径及其模式归属，阐明煤层群发育区煤层气开发模式的地质选择机制与选择方法，从模式层面回答研究区现有煤层气开发工程地质适配性与工程有效性问题，为煤层气开发技术与模式选择提供地质理论依据。

围绕煤层群发育区煤层气开发模式的地质选择问题，以黔西上二叠统煤层群发育区为例，采用多尺度表征模型叠加、能量转移机理、技术的地质匹配等思路与方法，揭示了煤层群背景下煤层气开发地质条件的特殊性与开发模式技术的地质选择性。基于研究区高应力、多薄中近煤层群发育、超低-低渗透性等特点，建立了煤层气开发基本地质构型，明确了沉积环境、构造应力作用下的储层参数动态配置与协同作用；以模型配置与协同作用为主线，基于关键开发地质条件提出了煤层气资源开发地质类型，并判断了黔西地区主要含煤单元的煤层气资源开发类型。深入分析煤层气开发技术的地质适配性和地质条件对开发工程的约束性，基于煤层气开发技术开发过程的诱导因子、储层能量转移耗散和过程差异，重建煤层气开发技术模式，并映射了其与煤层气资源开发基本地质类型的基本关系。基于黔西林华井田和松河井田煤系非常规气丛式井含气层组优先与评价、小层射孔、组段压裂的共采工程技术实践，归纳其工艺技术，探讨了煤系地层非常规天然气的匹配地质条件与开发地质类型。明确了不同开发地质类型的特征和识别标志，并依据开发地质类型和开发模式的映射关系和匹配程度，探讨了以黔西煤层群区为代表的煤层气开发模式的地质选择机制和过程，形成了煤层气开发模式的地质选择方法。发表学术论文30篇（含国际刊物4篇，期刊论文23篇），其中SCI收录2篇次、EI收录6篇次，部分成果与他人联合。参加国内相关学术会议4人次，协助培养研究生3名。