The Fine Description Of Chang6 Reservoir In The Middle And Late Stage Of The Development Of The Dalugou Second District, Jing'an Oilfield

The Chang 6 reservoirs in the infilled area of the second Dalugou area of Jing'an Oilfield belong to a typical ultra-low permeability lithologic reservoir.Since the implementation of major development test through the overall infill drilling in 2014,the research area has achieved certain development results.However,with the deepening of the development of the reservoirs,problems such as uneven water flooding in the infill drilling area and poor compatibility of well spacing patterns have become increasingly prominent,severely influencing the effect of the infill drilling adjustment of the reservoirs.In view of the imperfect injection and production well pattern and the large difference in stratified water flooding effect in the infill drilling area of Dalugou Second District,this paper provides a strong geological basis for the development of the Chang-6 Reservoir's development technology policy through the study of reservoir fine description.On the basis of comparative study on the strata division of the block in the past,the strata of the new infill wells were further finely divided,and the fine isochronous strata structure of the Chang6 reservoirs in the Dalugou Second District's infill drilling block was rebuilt and improved.Taking comprehensively a variety of sedimentary facies division marks as references,the sedimentary microfacies of the study area are analyzed in points-lines-surfaces,and the individual sand bodies are divided,revealing the genetic types of each sand body and micro-facies distribution.After comprehensive analysis,it is concluded that the Chang6₁² oil reservoir group in the study area belongs to the delta front sedimentary,in which the submarine distributary channel and the distributary channel flanks microfacies are the main sedimentary microfacies.The heterogeneity of the reservoirs are studied in details from the inside strata,inter-layers,and on the plane.The research shows that the heterogeneity of the Chang6 reservoirs is medium-to-strong.Finally,under the constraints of sedimentary facies and geological conditions,the three-dimensional geological model of the reservoirs was established by using Petrel geological modeling software,and this provides a reasonable geological basis for carrying out subsequent numerical simulation research and adjustment of development technology policies.