| Shiwu fault depression is located at southwest uplift area of Songliao basin, which is a small halfgraben-typed fault depression at the partial scope and a basin of single rifted sag at the lower part. The stratum from west to east pitch area ultra duplicated cascade, and restrains and attenuates suddenly to the north pitch. It is eroded from top to the bottom at the uplift spot of Dayangchangzi. This fault depression can be divided into five structural belts ---- west fault slope belt, north steep slope belt, middle structural belt, east gentle slope belt and double-dragon fault depression, and the total area is 1700 km2. The stratum types of Shiwu fault depression are determined by the form and evolution of the whole Songliao basin. And Shiwu fault depression is rich in oil and gas resources because of its special structure and deposition character.As a important tectonic element of Songliao basin, it has rich oil and gas resources, but its exploration and development have not yet a big breakthrough until now, which leads the low oil and gas output in that area. Doing the trap research and carrying on the trap appraisal to this area, is helpful for the development of the research on the trap system in this area, can provide the basis for the compilation of the exploration plan, and have certain practical significance on the optimization of the drilling target and the conjecture of well site, as well as the reduction of exploitation risk.A trap is the basic element for the accumulation and the essential condition of oil and gas. In each contents of trap appraisal, the geologic appraisal, which analyzes and appraises the possibility of oil and gas and its quality, is the foundation and basis. This essay uses the analytical hierarchy process, gray related analysis and comprehensive evaluation to do the trap appraisal the Shiwu fault depression and it coordinates the characteristics of the three (inaccuracy, uncertainty and partial authenticity) with the realistic system of the inaccurate, uncertain and partial authentic primitive data in trap geological appraisal. And leading these methods into the comprehensive trap geologic appraisal is an inevitability of the new quantitative appraisal methods of petrol-geologic science and exploration targets.Chief hydrocarbon source rock in Shiwu area is the melamudstone depositing at the era of Shahezi Formation and Yingcheng Formation. It has a high ratio of organic matter, and Typeâ…¡and Typeâ…¢of Kerogen are the main characteristics, and the evolutional degree reach to mature stage and high mature stage. Gujiazi-Houwujiahu region is considered as the center in plane. It provides a good condition for the migration of oil and gas. The most of the reservoir is sandstond and conglomeratic sandstone, which mainly occurs in upper Cretaceous series Quantou Formation, Denglouku Formation, Yingcheng Formation , Shahezi Formation and Jurassic Huoshiling Formation. The physical appearance of the reservoir is not very good, which located in Shahezi Formation and Jurassic Huoshiling Formation, Yingcheng Formation. The physical appearance of the reservoir is good ,which located in the top half of Denglouku Formation and the bottom side of Quantou Formation. Zonation on the NNE-NE direction of its partial structural zone is the main characteristic of the structural trap in Shiwu fault depression. In longitude, structural trap is formed above or below the interface of the fault-depression (named Quantou formation and Denglouku formation). No. 1 section, No. 2 section of Quantou formation and No. 1 section of Qingshankou formation can be considered as the regional covering strata. However, the partial beneficial regional covering strata in fault depression structure are growth in No. 3 and No. 4 section of Denglouku formation. And the chief hydrocarbon pool-forming patterns are self-generation and self-accumulation by primarily laterly migration, and the injection migration by primarily distal vertical migration. Oil-gas distribution is obviously determined by the hydrocarbon source rock and the tectonic activities.There are many parameters which reflect amount of oil and gas of the trap, and each parameter can only attribute one aspect of the amount of oil and gas of the trap. According to the reservoir theory, as well as the base of analyzing and researching the geologic feature of the trap and each factor of the token trap of Shiwu fault depression, we refer to the domestic and foreign experience on geologic appraisal of the trap, and have established the trap appraisal geologic parameter system that comprehensively considerate all elements which affect the accumulation of oil and gas, stresses the prominent master. The trap appraisal geologic parameter system appraises form four aspects: hydrocarbon source condition, the reservoir condition, the trap condition and the preserved condition, and it optimized 13 appraisal factors: the ratio of the hydrocarbon source rock organic, maturity capability of the organic, the distance of the hollow which form and drain of the hydrocarbon , the intensity of drain the hydrocarbon, the ratio of the sand and mud, the porosity, the thickness of the sandstone, the range of the trap, surface area of the trap, the depth of the main spot, the type of the trap, the thickness of the covering strata and the deposition of the covering strata. The appraisal formulates the geologic evaluation standard of the trap in Shiwu fault depression, and it comprehensively considerate the former research and experience, and combines the real petro-geologic condition in Shiwu fault depression, considerate the different geology effects on the reservoir at different areas.Weight factors determination reflects the importance of the geologic evaluation of the trap relatively, and its value affects the result directly. In the past, these synthetic weighting methods relay on the subjective judgment and experience. This article uses analytical hierarchy process to deal with the primitive data of the trap in Shiwu area, and utilizes the obtained the weight factors of the geologic elements, and avoid the subjectivity of the traditional method of determining the weight factors. In this way, the evaluation result is more objective, and the precision of the trap geologic appraisal is enhanced.This essay appraises the 28 traps of 11structures in Shiwu fault depression, which located in upper Cretaceous Series Quantou Formation, Denglouku Formation, Yingcheng Formation , Shahezi Formation and Jurassic Huoshiling Formation, by applying the analytical hierarchy process, gray related analysis and comprehensive evaluation. Compared with the three methods, they are different on their principles , the order of their obtained trap geologic appraisal qualities are more or less different, but their tendency are identical, especially the judgment on the relative preponderant trap. The results of the three are commonly the same, and have the partial comparability.There are 3 Typeâ… structures, 7 Typeâ…¡s tructures and 1 Typeâ…¢structures. 9 Typeâ… traps, 13 Typeâ…¡traps and 6 Typeâ…¢traps by applying the three methods. Specifically analyze the petrol-geologic features of the structures at Shiwu fault depression, the results of the three trap geologic appraising methods are mainly close to the reality. It proves that the three ways have their feasibility, and they also have some reliability at the choice of exploration targets. In the appraisal of exploration targets, we should utilize these three methods and more comprehensively, and achieve the multiple reasonable judging result.
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