The Description Of Reservoir Structure And Identification Of Fluid In Carbonate Rock

The area of sedimentary rock's distribution takes up 70 percent of our country, in which carbonate rock distribution covers about 55 percent(tour and geology resource), and that is one of the most important reservoir types. The latest oil and gas strategic report reveals that forland basin, paleohigh and marine carbonate rock are three important and significant exploration areas in our country. Thus, emphasizing the research of carbonate rock is very important.In the research of the thesis, we deeply studied the characteristic of carbobate rock reservoir structure and the various methods of fluid identification by the case study of Zhujiang formation in DW area, which is based on the difficulties of reservoir predicition, the seismic and logging response characteristics of reservoir in carbonate rock. First of all, we introduced the petrology traits, the pattern of precipitation facie and the sequence of strata in detail, and summarized the result of petrophysical test data analysis, the pattern of seismic response and the characteristics of logging. Secondly, we also introduced the technologies of seismic inversion and their application. After our research, the resolution of seismic profile after being processed is higher than that of seismic profile before that process, and the coutinuity of seismic event in horizontal direction is also enforced; the characteristics of wave groups are also improved in local areas, on which the width of spectrum is opened up. The result of three inversion methods keeps consistent on whole, but the resolution of the result in the prestack simultaneous inversion and union inversion is higher than that of poststack inversion, furthermore, the former can obtain the impedence of S-wave and density factors, which cannot be gained in poststack inversion. Thirdly, we paid more attention to discuss the research and application of carbonate rock rock structure and reservoir parameters. In the analysis of carbonate rock rock thin slice, we found that the shape of pore is so highly irregular that there is almost no method to model the pore shape just relied on the predecessors'assumed ellipse, round and coin shape, and so forth, or describe the change of these shapes using a analytical formula. Therefore, we built up the rock structure factor using classical petrophysic model with rock pore shape parameter, and discussed the effect to the elastic characteristic of rock and correlate the relationship between the factor and elastic modul through empirical and statistical analysis. The result of calculation of petrophysical data and logging data indicated that the tiny change of rock structure factor might influencethe calculation result of porosity severely. In the prediction of a single well porosity, we compared the prediction result using petrophysical model built in this thesis, which considered the effect of rock structure, with the result using conventional method, and we found that the former can improve the effect of porosity prediction and restrain the error cumulative phenomenon, in other words, we can improve the precision of porosity prediction beyond the given well. Because the petrophysical model described the various traits in rocks and built the essential correlation between the elastic characteristics and porosity, pore shape and other parameters for the inside rock mechanism, we can effectively describe various rock characteristic. Finally, we discussed several methods of fluids identification in carbonate rock.In sum, we can describe the structure of carbonate rock reservoir and identify fluids using above methods, and thus provide evidences for arrangement of well drilling and decrease its risk.