Optimal Design And Software Development Of Chemical Water Plugging With Multiple Slugs

Ansai Oilfield has been developed in the past 40 years,Some oil wells have entered the medium and high water development stage.The annual production loss is as high as 30×10~4t.The adaptability of conventional stimulation technology is poor,and it is difficult to stabilize production.Therefore,water plugging measures are considered for oil wells.This paper mainly passes the applicability of integrated analyzers in the Ansai oil field,and proposes the idea of optimizing the plugging agent.Based on the current development status,the geological characteristics and data of reservoirs,This paper studies the characteristics of high water-containing oil well and analyzes the reasons of water breakthrough mainly by reservoir heterogeneity,cracks,water injection development of influence,The main types of water visible are fracture,porosity and fracture-porosity water visible.Water characteristic curve method is used for the study area,a series of chemical water plugging measures effect evaluation in recent years,it is understood that although it has achieved certain precipitation.However,in general,there is a series of problems,such as"the plugging agent is complicated and the poor adaptability of the reservoir,the water is less efficient,the effect is very different."it is difficult to effectively support the continued stable production and production of Ansai Oilfield.The paper analyzes the main reasons why the application of multi-slug plugging agent system is not effective in water shutoff operation,and makes the optimization based on this,and analyzes that the other reasons are affected by reservoir geological characteristics,oilfield development status,construction parameters and field operation and other factors.Because the geological factors cannot be controlled by human,the influencing factors of well pattern are very complicated and difficult to be quantified.Therefore,it is necessary to optimize the existing chemical plugging agent and slug combination and construction parameters in Ansai oilfield.Based on the idea of optimizing plugging agent,This paper mainly evaluates the performance of the cross-linking polymer weak gel plugging agent and proves the plug agent can adapt to the formation conditions of the Ansai Oilfield;The pre crosslinked bulk particles of particle size(1mm?2mm)and expansion ratio(6 times)were selected,and it was proved that it had certain salt resistance,shear resistance,toughness and water retention property,and good mobility.The plugging rate can reach more than 97%,which can replace the existing pre crosslinked swelling particles and flow direction changing particles in Ansai Oilfield.In addition,a high-strength fracture plugging agent is introduced,which has a small hardness,strong flexibility,good viscoelastic,and has a strong compression resistance,and strong compatibility with formation water,etc.,which can overcome the pre-association of the pre-intersection-shaped pellets after a multi-wheel implementation application,which exhibits poor stability,easy to break,and gradually deteriorate,and can strengthen the plugging effect.At the same time,it is determined that the multi-segment plug in combination for the plugging of the Ansai oil field,Optimizing the process parameters of water plugging construction and introducing the preparation work and concrete construction steps before water plugging construction.On this basis,the water plugging software was compiled and developed.which is mainly composed of well selection decision-making module,plugging agent reservoir module,construction parameter design module,and water plugging effect evaluation module.By compiling water shutoff software,it can better meet the actual needs of Ansai Oilfield.According to the optimized design of the plugging agent system and slug combination,based on the optimization of construction parameters and the development of water plugging software,three high water-cut oil wells in Ansai Oilfield were tested for well Xing 67-22,Shan 040-49,and Shan 013-039.The well conducts pilot tests,and analyzes and evaluates the water plugging effect after construction.The results show that the water cut of well Xing67-22decreases to 64.5%after water plugging,the average daily oil increase is 1.04t,the effective period is 251d,and the accumulative oil increase is 249.25t.The water cut of Well Shan040-49decreased to 83.9%,the average daily oil increase was 1.58t,the validity period was 191d,and the accumulated oil increase was 327.81t.The water cut of well Shan013-039 decreased to56.7%,the average daily oil increase was 0.93t,the period of expiry was 302d,and the accumulated oil increase was 300.74t.Comprehensive analysis shows that the optimized and designed plugging agent system and slug combination are suitable for the geological characteristics of Ansai Oilfield reservoir,and can effectively block fractures,large pores and high permeability layers with remarkable water plugging effect,which can restore the normal production capacity of high water cut oil wells and improve the recovery degree of oil wells and the overall development level of the reservoir.