Study On The Relation Between Production Change And Connectivity Change Of Injection-Production Wells In Chang 6 Reservoir In Heishanliang Area Of Yanchang Oilfield

Heishanliang oil area is located in the middle of northern Shaanxi slope in Ordos Basin.Its main reservoir is Chang 6 reservoir of Triassic system,which was developed by water injection in 2010.However,at present,the production of oil well varies and the effect degree of water injection is uneven.The study on the relationship between the change of production and the connectivity between injection and production wells in a single well group is of great significance for the next step of water injection development,and the previous studies in this area are relatively weak.In this paper,the single injection production well group is used as the research unit to classify the production wells.By means of fine comparison of the corresponding horizon spontaneous potential curves,natural gamma curves and acoustic wave time difference curves between the production rising and falling production wells and the injection wells,the paper makes a fine comparison between the production wells and the injection wells by using the natural gamma curve and the acoustic wave time difference curve.In order to provide a new way for water injection development,this paper summarizes the variation characteristics of logging curves of production rising and descending production wells and water injection wells,and points out the changing trend of connectivity between production changes of production wells and injection production wells in order to provide a new way of thinking for water injection development.As a result of this study,the following awareness has been achieved:According to the variation trend of fluid production and oil production,42 production wells of ten well groups in the central part of the study area are divided into three types: up-production type(19 wells),production decline type(12 wells)and irregular production type(11 wells).In 28 groups of up-production wells and water injection wells,the change characteristics of logging curves of the two wells are as follows: from water injection well to production well,the negative abnormal amplitude of spontaneous potential curve increases in 23 groups,accounting for 82% of the total.The values of natural gamma curves decreased in 17 groups,accounting for 61%,and the values of acoustic time difference curves increased in 22 groups,accounting for 79%.The changes of logging curves between injection and production wells indicate that the permeability of sand bodies in the direction of production wells becomes better gradually.The muddy content decreased and the physical properties became better.In 17 production descending production wells and water injection wells,the change characteristics of logging curves of the two wells are as follows: from water injection well to production well,the negative abnormal amplitude of spontaneous potential curve decreases in 15 groups,accounting for 88% of the total.13 groups(76% of the natural gamma curve value)and 15 groups(88%)of the acoustic time difference curve value decrease.The variation of the logging curves between injection and production wells indicates that the permeability of sand bodies in the direction of production wells becomes worse.With the increase of mud content,the physical properties become worse.By analyzing the variation of logging curves between production ascending production wells,down production wells and water injection wells,it is found that from water injection wells to upward production wells,connectivity changes from difference to good connectivity,and from water injection wells to production decline wells,it is found that the oil wells from the water injection well to the upward recovery well have better connectivity,and that from the water injection well to the production decline type,Connectivity changes from difference to good,indicating that the change of connectivity between injection and production wells has a certain impact on production.According to the change of the connection relationship between different types of production wells and injection wells,the measures to convert some production descending production wells into water injection wells are put forward,and the relationship between injection and production is changed.In the new injection production relationship,the relationship between injection and production is changed,and the relationship between injection and production is changed.The connectivity from water injection well to production well is changed from difference to better,so that the output can be increased.