Dongpu Depression Wen 23 Gas Field Enhanced Oil Recovery

All petroleum production countries attach importance to the study of residual gas-oil and enhanced residual gas-oil recovery. Oil-gas field will come into the exploitation of medium-term or last-term after passing long-term exploitation, and there appear some correlative phenomenas such as high or special high water saturation in oil field, the pressure of gas reservoir and wellhead attainning abandonment pressure, the yield of oil-gas showing degression, much reserve existing gas-oil reservoir. The supply demand relationship of gas-oil becomes more and more lopsided in the world nowadays, through deeply knowing geologic background, studying the distribution of residual gas-oil, understanding and exploiting residual gas-oil in oil field, so enhanced gas-oil recovery become the best critical work in the oli field. The study about the distributing of residual oil with high water saturation and EOR are more, but the study of residual gas is less, especially for the tipical faulted standstone gas field with some characteristics such us low permiability, fringe-bottom water, massiveness and lamellar stucture.This article takes the biggest integral sandstone Wen23 natural gas fields having been developed in east as the research goal, and take the improving gas recovery as the research key, on the basing of gas reservoir fine description, with the theories of sedimentology, structure geology, reservoir geology, gas engineering, and the technique methods of Geoframe technical structure research, gas engineering method, simulation using Eclips, production log, and modern well test, and so on, establishes gas reservoir structure, the minor fault distribution and closeness, the reservoir, the insulation and the geological reserve distribution, on the basis of that, calculates the pressure drop reserve in different pressure regions, and research the gas reserves utilization condition and the producing character, research surplus gas distribution by simulation ,on the basis of simulating the present development situation, formulates enhancing the gas recovery technical countermeasure. There bring up some primary courses including advancing the perfect degree of gas well, ES₄3-8 with low yield returning ES₄1-2 gas reservoir, locally drilling adjust well, reforming gathering pipelines, respectively exporting gas with low-high pressure or addpressure to keep stable production and enhanced residual gas recovery. Through mending holes and fracturing in eleven wells, drilling four adjustable wellls in ES₄3-8 gas reservoir, the gas reservoir can steady production to 2007 and the gas recovery can advance 2.98% after sixteen years by prediction. It can prolong stable production three years and advance recavery 4.2% with commingled producting six low yield wells in ES₄3-8 gas reservoir and ES₄1-2 gas reservoir. When the exporting pressure drop from 3.92MP_a to 1.0 MP_a, the gas recovery advance3.6%.