3D Geological Modeling Of Multi-type Reservoirs And Numerical Simulation Of Co-mining Compatibility In Upper Paleozoic In Northern Zijinshan

3D geological modeling of multi-type reservoirs and numerical simulation of co-mining compatibility,which not only can express the geological structure and reservoir parameter spatial information intuitively and accurately,and can provide the key basis for co-mining development program,in order to ensure development and utilization of unconventional natural gas resources in multi-type reservoirs reasonably and sufficiently.In this paper,based on the systematic summary of the multi-type superimposed natural gas reservoirs and resource characteristics of Upper Paleozoic in the north of the Zijinshan,the 3D geological model was constructed by using Petrel geological modeling software,and the numerical simulation of multi-type reservoirs natural gas extraction selection area and layer were carried out by using Eclipse numerical simulation software,and a preliminary development scheme of mult-reservoir mining was proposed.The results showed that the whole structure of north of Zijinshan area is simple,and the coalbearing source rocks of the wide-generation hydrocarbon generation are overlapped with the tight sandstone reservoirs,coal reservoirs and mudstone reservoirs in large area,which was favorable for coalbed meathane,tight san gas and mudstone gas accumulation.The main coal seam has a large thickness and stable distribution,high gas content and good permeability,and is generally under slightly undervoltage condition.The tight sandstone reservoir is extensively developed and the space continuity is good,with high gas saturation,low porosity is lower,high permeability,reservoir pressure coefficient changes little,the majority concentrated in 0.6~1.1,which take under pressure as the principal thing and develop constant pressure reservoir.Coal-bearing shale gas content is very low,so the production potential is small,but coalbed methane and tight sandstone joint development resources potential.The 3D fine geological model of multi-type reservoirs gas,including structure model,facies model and phased property model,was established by using logging interpretation,seismic interpretation and stratification data,and its accuracy and precision are high.For the first time,the numerical test method of step by step stacking co-layer development and selection and the evaluation limit of co-minging are proposed.The preliminary selection of the work area and the layer are as follows: Taiyuan Formation sandstone as a whole suitable for single minging,and Shanxi Formation coal seam in the western part of the work area suitable for single minging,and Shiqianfeng Formation sandstone in the western part of the work area suitable for single minging,and the others suitable for co-minging.Among them,the co-minging layer combination as follows: Upper Shihezi Formation sandstone-Lower Shihezi Formation sandstone(A group),located in the area of the whole region.Lower Shihezi Formation sandstone-Shanxi Formation coal seam(B group),located in the southeast and northwest part of the most work area.Shiqianfeng Formation sandstone-Upper Shihezi Formation sandstone-Lower Shihezi Formation sandstone-Shanxi Formation coal seam(C group),located in the middle and eastern region in the area.