Well Test Analysis And Applicationin Of Xinghe Area

In oil field development process, people desire a more effective understanding of reservoir heterogeneity and reservoir property variations, providing the geological basis for the adjustment of the development program and the implementation of measures to increase production, and thus need a more perfect reservoir description method.Description of the oil and gas reservoirs typically rely on geology, well logging,core analysis, fluid properties analysis, well testing and other means to obtain information. These data complement each other。These means only well testing may describe the dynamics of oil and gas reservoirs, monitoring the changes of flow parameters.Through well testing, can determine the oil and gas reservoir model, the geological structure and flow parameters; can obtain reservoir capacity and the dynamic characteristics of hydrocarbon saturation.By well testing we can choose the most effective completion method, Evaluate reservoir damage,analysis damage mechanism and determine the oil and gas reservoir water power system range and ability.Through well testing can draw energy decline curves and IPR curves to determine the reasonable artificial lifting time and the optimal working system.The yanchang formation of Triassic in Ordos basin is a River-Delta-Lake sedimentary system which is formed under the condition of inland lake basin.It is a kind of hidden lithologic reservoir which has characters of low porosity, low (ultra low) permeability and so on。Reservoir in Xinghe area contains5laywes, Respectively is chang4+5、chang611-2、chang612、chang62、chang63.Under the existing economic and technological conditions,adopting Layered water injection and Commingling production, Economic benefit is well,but with the time prolonged, development contradictions become increasingly serious.In well test data interpretation process, Due to the lack of Interpretation standard, well test data Interpretation need more sufficient theoretical supports and guidances.Although obtaining a large number of data, application of Interpretation results is still insufficient. In order to study the geological features of Ansai oilfield XingheRiver area,support theory basis for oilfield rational development and stable production,carrying out the <<Well Testing Data Analysis and Application of Xinghe area>>project.This study based on a large number of literature research and summing up the results of previous studies,studing on Ordos Xinghe River area, focusing on Xinghe well testing curve classification, establishing the corresponding geological model and interpretation method.On the basis of the previous research,analysising the exiting data of Xinghe area, decomposing the skin factor, determining the main factor of Reservoir damage and reservoir property trend in Xinghe area; Through research and analysis, we get the following major findings:(1)Through the analysis of test data in recent years in the study area, summed up the main types of the test curves. We divided the curves into five categories, respectively are opening λ type curve, the small opening λ type curve, fractured curve, composite curve, early data without a bifurcation curve, different test curves represent different geological significance.(2) Based on the conclusion of regional curve type, combined with the well test theoretic geologic model,this paper clear the geological significance of each curves up,providing Interpretation standard.①The first, second kinds of curves should choose wellbore storage and skin factor+homogeneous reservior+boundary model for interpretation;②The third kind of curves should choose finite conductivity/infinite conductivity fracture+homogeneous reservior+boundary model for interpretation;③The fourth kind of curves should choose wellbore storage and skin factor+composite reservior+boundary model for interpretation;④The fifth kind of curves is unsignificant for conventional well test interpretation,can analysised by nonconventional methods.(3) Based on clearing all kinds of curves geological significance up. using the new interpretation standard,we choose typical well test datas to analysis and decompose the obtaining skin factors,the results of decompositions show the main factor for reservoir damage is mud filtrate.(4)Through summing up the well test data interpretation results, summed up reservior pressure, permeability variation trends, analysised its influence factors in study area.①Static pressure of production wells reservoir maintain stable, about1IMPa wave, plane distribution is not uniform; Static pressure of injection wells reservoir show a trend of increase,from19.76MPa to21.92MPa.injection-production balance is well.xIn the plane,permeability in production wells reservoir distribution is not uniform, with complex variation characteristics. From2001to2006,It shows a trend of increase; From2006to2009,It shows show a downward trend; From2009to2010, It shows a trend of increase, permeability in injection wells reservoir show a trend of increase.③With the production,fracturr half-length decreased,it shows that part of the hydraulic fracture closed.