Shale Oil And Gas Well Logging Evaluation And Application In Liaohe Western Depression

Liaohe western depression is a typical continental rifted basin with shale oil and gas resource potential in Liaohe region.It has important realistic significance to use well logging technology to evaluate the shale oil and gas of western depression.Through well drilling,well logging and core test data,the geological setting and shale oil and gas reservoir characteristics of Shahejie shale of western depression are summarized,on the basis of that,a set of shale oil and gas logging identification and evaluation method is studied out and has good application effect.?1?According to the rock physics model,under certain conditions,shale logging response value has a linear relationship with the percentage of organic matter,and the linear coefficient,which is big,is the difference between the logging response value of organic matter and other minerals.So a little change of the organic matter content has great influence on shale logging response value,which make the organic rich shale has"three high and one low"logging response characteristics.These are the important differences between shale logging response and conventional reservoir logging response.Different shale lithology have different logging response characteristics,and different types of shale are identified by star logging facies.The increase of organic matter and hydrocarbon are the main factors of the increase of acoustic time and resistivity respectively,and shale oil and gas are qualitatively and semi quantitatively identified by the method of acoustic wave and resistivity curve reverse overlap.?2?The sedimentary facies of shale are identified by gamma ray and resistivity logging curve combination feature,and the type of organic matter could be inferred from the corresponding relationship between the sedimentary facies and the type of organic matter.With the sedimentary facies as the unit,the TOC is calculated by multiple linear regression.By subsection fitting of the depth and the vitrinite reflectance,the logging evaluation of the maturity of organic matter can be realized.Shale is composed of brittle minerals,clay minerals and organic matter,and the clay mineral content can be logarithm fitted by TOC,which can be used to calculate the content of brittle minerals by TOC.Reservoir physical parameters can be obtained by using conventional reservoir logging calculation method.The gas content is calculated as the sum of adsorbed gas and free gas,and the adsorption gas is obtained by the linear fitting relationship of TOC,and the free gas is calculated by the gas saturation method.The oil content is obtained by using the oil saturation method or the movable hydrocarbon S₁logging evaluation method.?3?Research suggests that western depression have a shale oil and gas distribution model with“gas sandwich oil”section and“gas surround oil”plan.Based on this,a hydrocarbon bearing logging interpretation scheme is established,and well logging evaluation are carried out in the western depression.The impact factors of shale oil and gas are studied,on the basis of that the shale oil and gas reservoir quality parameters classification scheme are established,meanwhile shale oil and gas reservoir quality fast partition well logging plates are developed.Western depression Shahejie formation shale oil and gas favorable layer parameters standard are established,and combined with multi parameters overlap method and favor accumulate coefficient method the quantitative optimization of Shahejie formation shale oil and gas favorable areas are completed.Chenjia sag,Qingshui sag,Panshan sag and the surrounding area are suggested shale oil and gas favorable area of Shahejie formation.These set of shale oil and gas logging identification and evaluation method are combined with the geological features of continental shale in the western depression,and conform to the geological rule.It has obtained the good effect of evaluation,and has certain promotion value.