Research On Sensitivity Evaluation And Effective Development Method Of Low Permeability Reservoir

In the face of current energy depletion and other problems,effective oil and gas producti on has become an important problem to be solved.As an important part of unconventional oi l and gas resources mining,effective exploitation of low permeability oil and gas resources ca n properly alleviate the current resource shortage and other problems,and is an effective way t o ensure national energy continuity.However,the existing technology cannot produce low per meability oil and gas on a large scale.Therefore,the research carried out in this paper has gui ding significance for classifying low permeability reservoirs and selecting reasonable and effe ctive development methods according to different types of reservoirs.By referring to the data,this paper mainly uses the experimental methods of constant vel ocity mercury injection,nuclear magnetic resonance and physical simulation to study the char acteristics of the micro-pore structure,movable fluid,nonlinear seepage law and reservoir sen sitivity characteristics of Gaotaizi and Fuyu reservoirs,and makes a comprehensive classificat ion evaluation of the reservoirs.The results show that both Fuyu and Gaotaizi reservoirs sho w strong water sensitivity without obvious velocity sensitivity law,and the acid sensitivity da mage rate of Gaotaizi reservoirs is widely distributed from strong to weak.Fuyu reservoirs sh ow weak acid sensitivity,Gaotaizi reservoirs show medium to weak alkali sensitivity,and Fuy u reservoirs show medium to strong alkali sensitivity.The stress sensitivity of Gaotaizi reserv oirs is obviously lower than that of Fuyu reservoirs.According to the average throat radius,cl ay mineral content,percentage of movable fluid,pseudo-starting pressure gradient and crud e oil viscosity parameters,the reservoir classification parameter chart was established,and th e "block five-element classification coefficient" method and "plane five-element classificatio n coefficient" method were formed to conduct comprehensive classification evaluation betwee n and within blocks,and the reservoirs were classified according to the standard.Reasonabl e development technology and application conditions are given for different types of reservoir s.Finally,according to the development guidelines and policies of the oil field,the technica l and economic limits of effective utilization of low permeability reservoir reserves are calcula ted,and different development methods of different types of reservoirs are studied.It is clear t hat gas injection can supplement the energy better than water injection for class Ⅳ reservoir s.There is a big difference between the final recovery of water injection and gas injection i n Class Ⅲ reservoir,and gas injection can supplement formation energy more effectively.Bot h water injection and gas injection can replenish energy effectively in Class II reservoirs,but t he difference is not obvious.