| Hailar Basin has abundant oil and gas geological resource reserves.Because of the complex geological features,oil exploration and development faces many problems,which include inconsistent layer sequences division,uncertainty depositional system recognition,unknown rules of the sand body sedimentary evolution,etc..To solve the above problems,this paper dissects the sedimentary features to the typical block in the basin--Bei301 Block Nantun Formation 2nd member.The integrated application of geological,geophysical and drilling data,carrying out the study on the division and comparison of sequence,the certainty of depositional system and analysis of the sedimentary microfacies,etc..On this basis,predicted the remainder potential distribution in study area.According to the actual geological conditions of Hailar basin,intergrated sedimentology,sequence stratigraphy and high-resolution sequence stratigraphy methods,proceed the study of sequence stratigraphic framework,forming a set of fine comparison technology is suit for the complex fault block reservoir in Hailar Basin.Using of this technology to redefine the division of target layers in study area and to establish high-resolution sequence stratigraphic framework.Bei301 Block Nantun formation 2nd member can be divided into two long-term base-level cycles,four medium-term base-level cycles and seven short-term base level cycles.In the sequence stratigraphic framework,reservoir sedimentary theory as a guide,follows the principle of "large to small,former and later controlling",regional paleotectonic and paleogeographic study as the background,tectonic evolution and sequence filling pattern as the foundation,and further analyses the composition of depositional systems and sedimentary facies.Through the analysis to petrological characteristics,seismic reflection and well log response characteristics,it can be determined to the fan delta depositional system which is in the form of near source and rapid deposition.The study of sedimentary microfacies has broken with the traditional way,combining the advantage sandstone density with the sandstone thickness distribution,more reasonably associating deposition parameters with sedimentary microfacies,and repainted sedimentary microfacies of Bei301 block;constructively raises the zero value well point with the near well point together predict the sandstone thickness.Solving the difficult problems of sand body changing fast and sandstone prediction inaccuracies of complex fault block oil field,clears the rules of sand body distribution and sedimentary facies evolution,and establishes the sedimentary facies model of the study area.Studies have shown that Bei301 block Nan-2nd member belongs to the progradational fan-delta deposition,having the underwater distributary channel,overbank sand body,mouth bar,front sheet sand and turbidity sand.Based on the underwater distributary channel,from near to far source,the quantity is from few to even more,and the shape is from simple to complex,and often appears the mouth bar at the lake edge.This paper elaborates the reservoir lithology,physical properties and sensitivity characteristics of the study area,using of high-resolution sequence stratigraphy theory,discusses the development rules of the heterogeneity of the oil layer from the origin.Combination with the intergrated analysis of sedimentary facies distribution,reservoir contrast and dynamic production of oil and water,reveals the oil and water distribution rule,and there are five major favorable zones in the southeast,southwest and central parts of the Nan-2nd member ? and ? oil formation.Higher capacity wells are mainly located in the underwater distributary channel microfacies.? oil formation has better reservoir physical properties,sheltered by the fault in tectonic and the remaining oil is enrichment. |
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