A Study On Infilling Adjustment And Effect Evaluation Of Well Pattern In Block X Of WW Oilfield

Block X of WW oilfield was developed by vertical horizontal well pattern in 2003.The main development layer is the Putaohua oil layer with low permeability and ultra-low abundance.Due to the long development time,the comprehensive water cut in 2018 has reached more than 60%and entered the middle and high water cut period.In the development process,the well pattern is faced with such problems as imperfect injection production relationship,large difference in production conditions and serious flooding in the main block The key to the efficient development of oil field is to evaluate the development effect of water drive,study the distribution of remaining oil,and explore the well pattern infilling and injection production system adjustment mode suitable for the block.Based on the subdivision of sedimentary facies,using empirical formula,three-dimensional geological modeling,numerical simulation and other methods,this paper analyzes and studies the distribution law of remaining oil in block X of WW oilfield,designs and optimizes the infilling adjustment scheme suitable for the block according to the development characteristics and distribution law of remaining oil in the study area,and uses reservoir engineering such as A-type and C-type water drive law curve and empirical formula Methods:the static data and dynamic data of development before and after encryption in block X of WW oilfield are analyzed and studied.The geological characteristics and encryption adjustment effect are comprehensively evaluated and studied from 10 aspects,such as recoverable reserves and recovery factor,water drive control degree,water drive reserves production degree,cumulative water injection,water cut production ratio,etc.The study shows that the production status of each small oil layer in block X of WW oilfield is quite different.The remaining oil is mainly distributed in the main residual channel and the main thick sand.The remaining oil reserves of layer PI2₂-PI5₂ are large,accounting for more than 90%of the total remaining reserves.According to the formation reasons,they are divided into five types:imperfect injection production relationship type,plane interference type,interlayer interference type,fault edge type and sand body edge type Part type.After the infilling of well pattern and the adjustment of injection production system in block x,namely,the original horizontal well pattern,the fault edge of vertical well pattern,the center of well pattern and the edge of well pattern are infilled flexibly,and the long shut in oil well and water well are recovered.At the same time,the old well of original well pattern is converted for injection.The final recovery rate is increased by 4.0%,and the control degree of water drive reserves is increased by 3.8%,so as to improve the development effect of oil field.For other purposes Provide scientific basis for the next development of similar blocks.