Analysis On Architecture Of Sand Body In Lianhua Oil Layer Of Qi 40 Block

Qi 40 block is located on the slope-type complex oil and gas accumulation belt —the western slope of the western depression of Liaohe,and the petroleum geological conditions of Qi 40 block are favorable.After multiple explorations,several sets of hydrocarbon-bearing series have been discovered in the area,proving oil reserves available for industrial exploitation.At present,the exploration and development of Qi 40 block has entered the mid-late stage.The distribution of remaining oil is very complicated.The key research direction of this block has now become to the way to improve the recovery efficiency.For the above situation,using the data of Qi 40 block database,the architecture of sand body in the oil reservoir group I of Lianhua oil layer in Qi 40 block has been analyzed.Firstly,by dissecting field-exposed deposits and modern deposits in a similar depositional environments,and referring to domestic oil field research results of typical continental basin deposits,the basis for the division of single sand body configuration units is summarized;secondly,based on the consideration of the core well comprehensive column and logging data,we conducted research on single wells,sections,and planes,and finely described the single sand bodies of different genesis types in the oil reservoir group I of Lianhua oil layer in Qi 40 block and determined the size of the sand bodies,overlay patterns and spatial distribution patterns under the microenvironmental depositional environmental conditions,which can improve the accuracy of the description of the oil reservoir group,and provide persuasive geological basis for the formulation and adjustment of the middle and late stage development plans for the exploration of the block.By aligning the study of the oil reservoirs group I in the Lianhua oil reservoir of Qi 40 block,the following conclusions and understandings were obtained:(1)In the target study area,a reservoir classification system for the fan delta front subfacies was established.The 6th level is the spin-echo interface of fan-delta stacked leaflet,and the 5th level is the uni-genetic sandstone interface,the 4th level is the top or bottom interface of depositing underwater distributary channel microfacies.(2)The Lianhua reservoir in the Qi 40 block is the front of the fan delta deposition,and three sedimentary microfacies of underwater distributary channel,channel edge,and inter-branch bay are identified,and the characteristics of lithology,physical properties and thickness,and electrical characteristics of different sedimentary microfacies during spatial distribution are clarified.(3)In the target study area,submarine distributary channels,river channel edges,and tributary bay sand bodies,which are divided into sedimentary sand bodies of the fan delta,have developed muddy interlayers and channel retention deposition.Due to the frequent overlapping of different sand bodies,the stacking styles are various,many kinds of sedimentary structures are deposit.The features of the configuration are complex,and the heterogeneity is strong.(4)In the study area,a typical well group was selected to establish a reservoir configuration model in which the sand bodies of underwater distributary channel,the distributary channel,and the tributary bay of the fan delta sand body were superimposed,and the distribution characteristics of the oil layers were clearly defined.(5)Since the deposition features controlled general environment have been macro analyzed,in the plane,multiple phases and multiple sand bodies were superimposed on one another,the plane distribution of the superimposed sand bodies is characterized by the late depositional sand body thickness becoming smaller than the early period.Generally,the eastern part is better developed than the sand layer in the western part of the area.The oil layer has good local connectivity in the plane and the overall connectivity rate is low.