Reservoir Architecture Of 9-10 Unit Of The Second Member Of Shahejie Formation In Tuo28 Fault Block, Dongying Depression

In the development course of more than 40 years,Tuo28 fault block of Shengtuo Oilfield has gone through the natural energy development stage and waterflood development stage,and has now entered the ultra-high water cut development stage.There is serious flooding phenomenon in the reservoir,the remaining oil distribution is scattered,and the cost of production and development measures is rising year by year.At present,the refined study of reservoir architecture and the low understanding degree of sand body connectivity under high precision sequence stratigraphic framework have become the main problems in the fine development of remaining oil in this area.Based on a large number of logging and logging data,this paper has carried out high-precision sequence stratigraphy,sedimentology and reservoir geology research for the 9-10 sand formation of the second member of Tuo 28 fault block.On the basis of high-precision sequence stratigraphy research,the multi-order configuration of the target interval has been dissected.The main research achievements and understandings are as follows:The high precision sequence stratigraphic framework of 9-10 sand formation of the second member of Tuo 28 fault block has been established.Based on the base-level cycle theory and high-resolution sequence stratigraphy theory,the 9-10 sand formation of the second Member of the Shahejie Formation was divided into 2 medium-term cycles,6 short-term cycles and 12 ultra-short-term cycles by comprehensive use of logging and core data,which laid the foundation for the next step anatomy of different configurations.A new type of configuration unit has been identified and divided.There are three types of units in the study area: estuary bar,braided river channel and far-sand bar,among which the estuary bar is the most widely distributed.Because the target member is in the semi-cycle where the long-term base level becomes shallower upward,the bottom of the 9 and 10 sand formations are dominated by semi-deep lake and far sand bar deposits,and gradually transition to braided river channel and mouth bar deposits at the top.The connectivity and development rules of sand bodies are re-recognized.Although the well pattern has been encrypted for many rounds,it is still unable to achieve the overall control of the sand body.The overlapping and cutting relationships of underground sand bodies are complicated,the contact and connection relationships are unclear,and the composite sand bodies show strong heterogeneity.Multiple advantageous waterflood channels are formed in the study area,which makes it difficult to develop the oilfield fine.On the basis of high-precision sequence stratigraphic framework,combined with dynamic data,the target sand body was dissected and re-characterized step by step,and the three-dimensional model of sand body distribution and sedimentary facies distribution was established.The distribution and development pattern of septum and interlayer were established.The location of interstitials and interstitials was identified in a single well,and the distribution of interstitials and interstitials was described in a three-dimensional model based on the theory of base-level cycle change and dynamic data.The distribution model of interstitials and interstitials in the target interval was established,and the favorable area of remaining oil distribution was predicted.Through the research,the architectural model of braided river channel,estuary bar and far-sand bar was established.The spatial distribution of different architectural units was described through three-dimensional geological modeling,and the development model of interlayer was defined to provide technical support for later development.