The Caprock Quality And Gas Accumulation Characteristics Of The China’s Large And Medium Gas Ifelds

Along with our country have been discovered Carat2,Sulige, Puguang such as airreservoir. On the natural gas exploration and development knowledge is more and more high.China is now found in large and medium-sized reservoirs has more than hundreds of. The gasreservoir formation is inseparable from the caprock on reservoir closure and preservationeffect. For our country now large and medium-sized statistical study found, According to itsdifferent reserves abundance, it can be divided into high and low abundance gas reservoir.According to the different reserves abundance gas reservoir for statistical study found,These reservoirs not only in Oil and gas generation, there are some differences of reservoir,The sealing conditions also have certain differences. Through the existing data and publishedliterature, Summary of high school low abundance gas reservoir caprock distribution layer,nature, distribution law and different abundance gas reservoir caprock development pattern;Different abundance gas reservoir caprock microscopic seal difference. Obtain the highabundance of gas accumulation period is late, Cover layer formed late in the era, cover layerthicker, more widely distributed, rock plasticity strong, with replacement pressure and othercharacteristics of gas reservoir with low abundance without distinction, has separated betweenlocal cover as well as gas reservoir development, cover the lower displacement pressure andso on.The oil and gas drilling and seismic data, combined fracture on the cover layer has greatinfluence on the coupling relationship between the two. Sum up its to form differentabundance gas reservoir plays a role as: High abundance gas reservoir is development of fault,conducive to oil and gas migration and accumulation, but the fault disappears shale smearingin the cover layer or with a closed. Development of gas reservoirs with low abundance doesnot break, Development of only a small number of faults, cracks can increase persuasionability that the large area of oil and gas reservoirs. Summarizes the two models: total controlof local block local covers large areas of low-efficiency gas low abundance of gasaccumulation patterns, regional cover mass efficient gas high abundance of gas accumulationmodel.