Application Of Integrated Geophysical Interpretation Techniques

Southern marine carbonate complex geological terrain and harsh naturalenvironment can be easy to form interference wave, and the area of near-surfaceexposed limestone layers have a strong attenuation effect, they all restricted the use ofconventional seismic method of oil and gas exploration in the area. And singlegeophysical methods are easy to create multiple solutions, so the oil and gasexploration in the area must be based on its specificity, using a combination of avariety of effective exploration methods to complete the exploration of the target.Especially electromagnetic methods, with Magneto-telluric as the principle method,are immune from high-resistance shield and have a high penetration depth andadvantages of strong adaptability of South complex mountains, so they are playing anincreasingly important role in oil and gas exploration in the South.The main objective of this paper is to complete the DZ sectional comprehensiveinterpretation of petroleum geology and geophysics with non-seismic geophysicaldata and physical property data as well as oil and gas geological data. To understandthe DZ sectional deep basement features, longitudinal and transverse structuralcharacteristics of electrical layer, typical structure and fracture’ development and thedelineation of favorable oil and gas structures in the area, and providing a referencefor subsequent hydrocarbon prospect evaluation and selection favorable block, weproposed a set of oil and gas geological-geophysical integrated interpretation methodsby integrating electrical method (MT), gravity and magnetic data and based onpetroleum geology theory and properties data.This paper noted DZ section have a premise for comprehensive geophysicalinterpretation,starting from the basic theory of non-seismic gravity exploration,magnetic exploration and electrical exploration., and summarized the establishedtheoretical reservoir model’s corresponding gravity, magnetic, electrical geophysicalanomalies, and pointed out that it’s difficult for division of reservoir narrowly andmeet demand for oil and gas, but we can indirectly reach the looking for oil and gas by qualitative interpretation and quantitative interpretation of electrical data,and byprocessing and modeling and inversion of gravity field data,we verify the reliabilityof the MT interpretation and studied the deep interface depth and interface localstructures. In addition, through a joint analysis of geophysical data and graphic data,the typical structure and fracture of the section and fracture were studied, andultimately get a comprehensive explanation of the results of a diagram of DZ section.Finally, since the purpose of this comprehensive explanation is for the services of oiland gas exploration, so the paper analyzed the favorable reservoir-cap portfolioaccording to petroleum geological data and summarized its geophysical anomaly.The results showed that: In the middle and eastern of the section developed upthree sets of electrical layer, and they are significantly affected by tectonicdeformation, while the western section can develop five sets of electrical layercompletely, its reservoir-cap portfolio’s tectonic deformation is relatively weak, so it’sfavorable zone for oil and gas exploration. In short, this petroleum geological andgeophysical integrated interpretation achieved good results, it verifies the feasibilityof the integrated interpretation method in the area.