Study On Remaining Oil Distribution And Adjustment Plan During High Water Cut Stage Of Fault Block Ha 301

Fault Block Ha 301 has entered high water cut stage after more than 20 years of water injection development.At present,there are some problems such as single direction of effect,prominent contradiction between layers and complicated distribution of oil and water.It is becoming more and more difficult to tap the potential of remaining oil.Through reservoir engineering and numerical simulation in this paper,the remaining oil characteristics of Fault Block Ha 301 are analyzed,and the design,development and adjustment plan is optimized to provide technical support for improving the development effect of this block.First of all,according to well logging and drilling data,the study of three-dimensional modeling is carried out in order to find out the spatial distribution characteristics of reservoir,sand body and single sand body,confirm connectivity and deepen reservoir recognition;Second,according to production data,the effect of water flooding is evaluated;Third,through the research of numerical simulation,the distribution and migration of reservoir fluid and the distribution law of remaining oil are Fig.ured out;Finally,the integrated development and adjustment plan is completed,and the development effect is predicted.The study results show that there is still a large amount of remaining oil.It is mainly influenced by imperfect perforation,unreasonable injection-production relationship,one-way effect,unobvious effect of water flooding,fault sealing and sedimentary microfacies etc..The plane distribution shows:The main type is large area distribution,accounting for 64.44%of the total sedimentary unit;The remaining oil mainly distributes in the poor effective direction;The main types of the weak flood areas are one-way effect,imperfect injection-production and no perforation.The vertical distribution shows:The recovery degree of sub oil group A?s is the highest which reaches 29.68%,followed by sub oil group A?z and A?x whose recovery degrees are 26.61%and 27.21%respectively;From the point of oil groups,the recovery degrees of A?oil groups are significantly higher than that of AII oil groups.In view of the development problems such as low producing degree of water drive,unreasonable injection-production ratio,the heavy building pressure phenomenon of formation,imperfect injection-production pattern development etc.,the development and adjustment plan of Fault Block Ha 301 is made according to different zones and different layer series:First,improve the injection-production pattern,optimize and adjust the layer series,change the oil displacement directions and raise the fluid in the water injected zones;Second,on the basis of the first batch which is implemented successfully,further perfect well patter and improve raising fluid in low permeability formations.After the implementation of the plan,the water flooding recoverable reserves increases from 186×10~4t to 210.0×10~4t,the water flooding recovery ratio increases from 31%to 35%,and the cumulative increased oil production is10.5×10~4t in ten years.