Study On The Selection Of High-efficient Oil Displacement Systems And Process Optimization Of LD Oilfield

With the rapid development of China economy, more oil resource are desired. However,onshore oil reservoir has been in the middle or late stage of development and hard tostimulated. Offshore oil resources are abundant in China. Oil reservoirs in Bohai Bay havebecome China’s third biggest oil production base, in which heavy oil forms a large proportion.So it is put more importance to develop the offshore heavy oil faster and efficiently. Selecteffective surfactant that are suitable for active water flooding of LD block.Aiming at studying the different kind of heavy oil in LD block of CNOOC, SARAcomponent, element, acid number and polarity of heavy oil are tested to investigate the heavyoil physical properties of target area. With the programmable rotary viscometer and hightemperature high pressure rheometre, the influence of temperature and rate of shearing toheavy oil’s rheological property are analyzed, fitting the experiment results data, concludingthe constitutive equation of heavy oil at different pressure. Four kinds of surfactants (A205、ZKS-1、QY-1and UT8-1A) are studied for their effect on emulsification viscosity reductionproperty, and two of them are selected (ZKS-1and A205).In order to evaluate the two surfactant’s water flooding effect further, the hightemperature high pressure laboratory displacement equipment is used to research the artificialcore and evaluate its displacement efficiency to select ZKS-1as the fittest surfactant of thehigh effectively developing target area. Following its displacement efficiency is studiedthrough three aspects, including injection time, oil viscosity and heterogeneity. Based on this,ZKS-1’s mechanism of improving the water flooding efficiency is known further more.What’s more, according to the result of displacement experiment, the optimum concentrationof ZKS-1used in LD block is put forward, that is600mg per liter. The research providestheoretical foundation of high effectively surfactant flooding development of heavy oil in LDblock of CNOOC.