The Chuandong Large Pool Of Dry Wells Constructed With Ka-~ 2 ~ Ka-1 Reservoir Characteristics And Reservoir Prediction

Carboniferous System is the main pay formation of Dachiganjing structural belt in east Sichuan, but, it has been entering into the middle-late periods through being exploited for many years. so, it needs finding new substituted pay formation urgently. In the T₁j² stratum which was the passed by stratum of Carboniferous, especially in the T₁j²₂—T₁j²₁ sub-stratum, there were not only well drilled show, but also had got industry productivity, so, these show that there are well exploration foreground in T₁j² stratum.The research of reservoir characteristics indicate that the T₁j²₂ reservoir's pore spaces were dominated by intercrystalline pores and corrosion pores, there have 1 ² high porosity section by corrasion in Mainan structure, the porosity is 6¹6%,and in this area reservoirs mainly belong to type Ⅱ and typeⅢ, the reservoir type was defined as fracture-pore type. and the reservoir physical property were primarily dominated by sedimentary fades, corrosion and dolomization. The reservoir type of T₁j²₁ was defined as fracture type, it has the obvious characters of low porosity and low permeability. The growth degree of the structural fracture has pay main influence to the reservoir quantity.In the prediction of T₁j²₂ reservoir, we analyse reservoir's seismic response characters through 2D seismic forward model which was base on the lithology and Reservoir characteristics in the research region. Then picked out the seismic inversion method through the sensibility experiments, at last, we choosed Strata block inversion to predict T₁j²₂ reservoir. For the sake of high precision of reservoir prediction, we introduce the synthesis method of velocity inversion and pattern recongnition to pridict reservoir synthetically. The T₁j²₁ reservoir is fracture type, so the point of reservoir prediction was fracture prediction. This text introduced the synthesis curvature method for fracture prediction for the first time. Firstly, we choose three mathematic method to calculate line curvature and surface curvature in the same gridding node, then, through standardization processing, picked the max curvature value to draft curvature contour map, and set the lower limit of curvature value base on production test and drilled show, at last, we block out the fracture upgrowth areas. This new method has better effect than single curvature calculate method.Reservoir prediction display that T₁j²₂ reservoirs are comparatively steady in portrait, and are flaky in the plane. Reservoir in south structural belt developed well than north, which concerned not only the reservoir thickness but also reservoir physical property. The T₁j²₁ reservoirs are lenticularly developed in portrait with bad stratification, and reservoir thicknessare smallness.In conclusion, through researches of reservoir characteristics, reservoir prediction and the relationship between reservoir and trap, it indicate that Mainan structure and Mopanlaowan buried structure which was in the bottom wall of the fault were the chief exploration and drilling regions of T₁j²₂^T₁j²₁ stratum in Dachiganjing structural belt.