Technology Of Increasing Injection And Optimization Of Injection Parameters For The Water Flooding Of Tertiary-main Layers In North-one Area

The geological reserves of tertiary-main layers are abundant, whose development modeis mainly in waterflooding, furthermore, tertiary-main layers are the main exploration objectof twice and three times waterflooding at present time. But its type of sand body is front sheetsand, and for the tertiary-main layers, because of multiple layers, thin thickness, lowpermeability, great physical properties,stray remaining oil distribution, which is hard to tapthe potential. For the characteristics of tertiary-main layers on North One area, the reservoirproperty is researched, high pressure of water injection is analyzed, the property ofantihypertensive agent is evaluated and the experiment of increasing injection is researched,different surfactant systems and injection rate on waterflooding enhanced oil recovery are alsodiscussed.The results showed that: the growth of rock pore is poor to medium in North One area,the porosity is mainly the kind of intergranular pore and dissolution pore,and the connectivityis poor; there is scale in injection water, the particle diameter of suspended matter is big, thecontent of iron ion is relatively high, and water injection will cause the blockage of formationthroat; the critical salinity of salt sensitivity in reservoir is7000-10000mg/L, there is mediumweak water sensitivity,velocity sensitivity, alkali sensitivity,and medium srong acid sensitivity;There is good compatibility between experimental wastewater and selected surfactant, thereexists no precipitate, the interfacial activity of surfactant system which is made with sewage,the interfacial tension can be reduced to10^-3mN/m; The antihypertensive rate of betaineactivity system that added clay stabilizer is higher than single betaine activity system, theantihypertensive rate of weak base with petroleum sulfonate system is lower than resistantscale agent with petroleum sulfonate, the antihypertensive rates of four surfactant systems are25.13%、23.78%、19.86%、22.66%; With the increase of the injection rate, antihypertensiverate of betaine activity system rises at a small scale; antihypertensive and injection increasedexperiment showed that the system which were researched can greatly enhance oil recovery inthe homogeneity core.