基于相控的煤层气藏三维地质建模

煤层气藏是一种非常规天然气藏，与常规天然气藏在赋存方式、物性参数以及开发方式等方面存在较大差异。煤层气藏三维地质模型能够精确描述煤层以及物性参数空间分布，推动煤层气藏的认识由定性向定量的转变，对煤层气藏的开发具有重要意义。以澳大利亚B区块煤层气藏为研究对象，综合应用地质、地震、测井、煤岩取芯分析等资料，分析构造解释的煤层层面、测井精细解释结果以及物性参数精细表征结果；借助Petrel三维地质建模软件，以地震解释煤层顶面构造和断层结果为数据基础，以测井煤层划分结果为约束条件，建立B区块构造模型；在构造建模基础上，以测井资料划分的单井岩相数据为基准，建立煤层相模型；煤层气藏物性参数建模以相控建模理论为指导，以煤层气物性参数表征结果为数据基础，实现干燥无灰基含气量、渗透率、密度、灰分含量、饱和度等物性参数空间分布模拟。在建立的三维地质模型基础上，利用煤层气藏储量计算方法，计算B区块地质储量，确定B区块煤层气有利区优选物性参数及标准，划分煤层气藏有利区。煤层气藏三维地质模型为煤层气藏地质储量计算以及有利区筛选奠定坚实的地质基础，同时也为井型选择与井网布置等后续开发工作提供地质依据。

Facies-controlled Three-dimensional Geological Modeling for Coalbed Methane Reservoir

Coalbed methane reservoir is a unconventional natural gas reservoir, and is bigger different from conventional natural gas reservoir in occurrence mode, coalbed parameters and development method. Three-dimensional geological model of coalbed methane reservoir accurately describes the spatial distribution of coalbed methane parameters, effectively promotes the change of coalbed methane reservoirs from qualitative to quantitative, and also has important significance for the development of coalbed methane reservoirs. Taking the coalbed methane reservoirs in block B of Australia as an example, the geological, seismic, logging data and coring analysis data were selected, and the precise interpretation results of the coalbed surface and logging were analyzed, and the precise characterization results of coalbed methane parameters were discussed; based on the top surface and fault seismic interpretation results of coalbed, the structural model of block B was built in the constraint condition of logging coalbed division using the three-dimensional geological modeling software Petrel; and then, the facies-controlled coalbed model was built based on the lithofacies of single well interpreted from logging data; according to facies-controlled modeling theory, based on the characterization results of coalbed methane parameters of reservoir, the space distributions of coalbed methane parameters (such as gas content of dry ash-free basis, permeability, density, ash content and saturation) were simulated; according to the three-dimensional geological model of coalbed methane reservoir, the geological reserve of block B was calculated, and the favorable parameters and criteria for favorable areas of coalbed methane reservoir were determined, and then, the favorable areas were divided. The established three-dimensional geological model of coalbed methane reservoir has important significance for the calculation of geological reserve and the division of favorable areas, and also provides the geological basis for the follow-up development of well pattern selection and layout of coalbed methane reservoir.