Well Logging Interpretation Of Carbonate Reservoir

The carbonate rock reservoir compared with clastic reservoir has a great feature isthe carbonate reservoir can be corrosion, corrosion may be the formation of karst cave.Void space structure cave reservoir than voided type and fracture type reservoir arecomplex, and the degree of anisotropy is greater. Therefore, cave reservoir in welllogging interpretation and evaluation of the difficulty is voided and fractured reservoiris much greater. Cave reservoir has always been an important subject of Chinese andforeign scholars, and also is one of the most difficult frontier problem in well logginginterpretation.Oil and gas reservoir of carbonate reservoir occupies a very important position,cave reservoir is a very complex type of carbonate reservoir, therefore, domestic andforeign experts、scholars have studied many logging interpretation and methods ofcarbonate cave reservoir has done a lot of work. Due to the current logging andlogging methods, study and instrument most methods are the formation of vast ashomogeneous formation to the model, but the carbonates Cave reservoir with stronganisotropic, therefore, has not yet formed a set of relatively well logging system withperfect interpretation and evaluation carbonates Cave reservoir.In this paper, the above problems and the research direction, focus on, on thebasis of previous research, study and improve on some of the problems encountered incarbonates Cave reservoir logging interpretation, starting from the actual data, bycombining theory and practice, to establish a set of logging interpretation atcarbonates Cave reservoir is relatively perfect and practical method. This study as afrontier subject in the study of China’s oil and gas logging, the result of the researchcan improve and enrich the carbonates Cave reservoir in well logging interpretationand evaluation method in theory and application level. In view of some logging, geological cave reservoir characteristics from thefollowing aspects:One，Research on formation mechanism and geological characteristics of thecave;Two, to carry out research on development characteristics of cave, find out thegeological, drilling and logging on logging identification;Three, to carry out research on cave reservoir logging identification methods,focus on how to use the conventional logging data, logging data imaging recognitionof cave, and determine the size and the filling degree of cave;Four, to carry out distribution of cave reservoir and Study on fluid nature, and thelogging cave reservoir interpretation and evaluation method of test application resultsthrough examples.Through a series of studies, scheduled for completion by the content of carbonatecave reservoir, and has made the research results of the development of the subjecthas important significance and practical production:1、 based on research on causes, detailed summarizes several types andcharacteristics of the cave. Study on the distribution regularity of karst cave, in thelongitudinal, transverse and distribution characteristics of ancient landform, providesthe geological basis to some extent for the fluid properties of carbonate cave reservoirdiscrimination.2、establish the carbonatite logging cave reservoir model. Numerical simulation tothrough bilateral, theoretically has analyzed the characteristics of shallow lateralresistivity curve may appear in the form of conventional cave; curve, electricalimaging logging cave recognition criteria, and then computing the cave filling degreefor half filling karst cave; Exploratory of the cave size estimates, and points out thatthe electrical imaging data to estimate a misunderstanding the size of the cave.3、establish a set of carbonates cave reservoir discriminant validity and logginglogic series method. The formation of the filling karst cave (breccia filling, mudfilling) effective reservoir identification applicable standards; development of mudfilling cavern reservoir discriminant chart, effectively judge whether filling layer withproduction conditions; logic judgement method for direct identification of unfilled,half filled karst cave reservoir fluid properties.4、 The original macro distribution of formation fluid, according to themorphology and storage cavern possible way, divided edge water model, bottomwater, isolation, isolation mode water gas geological model, combined with the logic discrimination curve method and pressure to determine fluid property.5、According to the pore formation fluid in very complex fracture type reservoirand intergranular pore is the mud breccia filling karst cave reservoir quality fillinglayer establishes movable fluid identification of fluid properties, and achieve betterresultsThis paper studies the theory combined with practice, proceeding from realitythrough theoretical analysis, model establishment, the actual production results andlogging data analysis and research, explained the application and verification ofevaluation methods in Tazhong area to establish a set of carbonates cave reservoirlogging, obtained certain result. Therefore, not only has a strong theoreticalsignificance of this research, and also has a strong practical value.