Fault Characteristics And Controlling Function Of Oil Accumulation In Zhao 41~zhou 58 Block In Songliao Basin

By the study of information system of three-dimensional seismic interpretation in Zhao 41 - 58 block, detailed analysis of the geometry of the fracture, the study area has developed the lower vertical and central fault system, the upper part of the fault system is minimal. Presents a variety combination mode in vertical, there are mainly "flower" combined mode and the "cut-base" type of combined models. T11 reflective layer developed multi-directional fault zone, on the profile there are 'like flower-like' and 'V shaped' combination model. Fault dense belt is wide on T11 reflective layer, scale of faults is small, and the faults on the edge of the belt is that some faults on the edge of fault condensed belts of F,y oil layer up to P oil layer.Fault activity period in the study area during the total 7: Early Cretaceous,Late K1q～early K2qn sedimentary period,K2y sedimentary period, K2n1,K2n2 sedimentary period,they are a period of extension ; final K2n sedimentary period,final K2m sedimentary period,final E2y sedimentary period for the three strong squeeze. Faults has gone through the formation and evolution of extensional deformation of K1h～K1sh sedimentary period; mainly transtensional deformation of K1d～K2n1,K2n2 sedimentary period; K2n3～the fourth line was stressed by NWW Field reversal occurs mainly deformation.According to the formation period, the variability features (extension, transtensional and strike-slip) and the formation and evolution mechanism of the fault ,the study area shows that a total of 6 types of fault systems development: the faults formed in faulted period , the faults formed in depression period, the faults formed in reversal period ,the faults formed in faulted period and continuous actives in depression period, the faults formed in faulted period and continuous actives in depression and reversal period, the faults formed in depression period and continuous actives in reversal period. The faults formed in faulted period and continuous actives in depression and reversal period and the faults formed in depression period and continuous actives in reversal period are mainly source fault types in P oil layer.Based on the division of the fault system, through the data of several wells in the study area, to study the the oil distribution and reservoir type of Zhao 41– Zhou 58 block , and the reservoir type mainly are fault block oil reservoir, fault seal oil reservoir and fault - lithology oil reservoir . According to the results of fault system classified, and the distribution of reservoir type and the controlling function of faults to oil and gas will classified the fault-related traps of Zhao 41– Zhou 58 block of to two categories and four types: the fault block trap, the fault sealing trap, the fault-lithologic trap.Though the controlling function of faults to the oil accumulation and the characteristic of oil accumulation and distribution of Zhao 41– Zhou 58 block, reservoir controlling mode of the fault can be divided into three types, namely, the vertical migration and fault sealing reservoir controlling mode in oil source area, the vertical migration and sand lateral migration fault sealing reservoir controlling mode in oil source area, the vertical migration and fault sealing reservoir controlling mode outside of oil source area.