广西百色盆地油气综合化探方法研究及效果

A STUDY OF GEOCHEMICAL EXPLORATION TECHNIQUE AND ITS EFFECTS IN BAISE BASIN,GUANGXI AUTONOMOUS REGION

本文探索油气综合化探方法在广西百色盆地寻找油气田有效性试验。研究结果表明,用土壤吸附烃、蚀变碳酸盐、吸附相态汞、电导率、卤素5种方法,重烃、甲烷、乙烷、雨烷、正丁烷、汞、蚀变碳酸盐、电导率、碘9项指标圈定油气田分布区和寻找油气田具有效性;研究了上述各项指标在油气田(藏)的周边或顶部的不同晕效应及其与油气分布的关系。指出综合化探异常在油气田或油气藏中心向外具有:汞→烃类、电导率→ΔC→碘异常的水平分带特征。依据上述异常特征建立出油气综合化探异常模式,并在百色盆地未知区圈定油气有利聚集带,结果在化探 I-16号远景区经钻探验证,打出工业油气。

A study of the effectiveness of geochemical exploration technique for oil and gas in Baise basin,Guangxi autonomous region demonstrates the ef- fectiveness in the delineation of oil gas region as well as oil and gas reserv- oirs by means of following five types including nine indices,soil adsorbed hydrocarbons(C_2^+,CH_4,C_2H_6,C_3H_8,nC_4H_(10)),soil eroded carbonates(△C),adsor- bed mercury(Hg),electrical conductance (K_8)& halogen(I_2).Adsorbed hydro- carbon and non-hydrocarbon indices exhibite ring-,haIf ring-,harbor-like and concentric forms,ie.faint effect,around an oil or gas reservoir mainly;in these ring-like abnormalities the relative low region corres-ponds to the ce- nter of an oil or gas reservoir or an oil and gas region.Hg abnormality for- ms top faint mainly just above an oil or gas reservoir,and the abnormally high region corresponds to the center of an oil or gas reservoir or an oil and gas region.I_2 demonstrates large ring-like fainting effect around an oil reservoir,and exhibits a top fainting effect in the case of a gas reservoir. The comprehensive geochemical,abnormality shows a feature of Hg→hydro- carbon,electrical conductance→AC→I_2 radiating from the centre of an oil or gas reservoir laterally. A geochemical exploration model for oil and gas has been constructed based on the above features,and has been applied in Baise basin to point out favorable oil and gas accumulation area.Commercial oil and gas flow has been obtained by drilling in geochemical exploration region 1-16.Thus the effectiveness of such a model is demonstrated.A complete set of geochemical exploration technique effective in searching oil and gas reservoir in medi- um-small basins in southern China is presented in this paper.