The Experimental Study Of Polymer Flooding In LD10-1 Oilfield Of Bohai Sea

Lvda 10-1 Oilfield is located in Liaodong Bay of Bohai Sea,which was put into production smoothly on January 28th,2005,and which is the first oilfield that have put into production in Lvda oilfield groups. The reservoir has the characteristics of high temperature, high salinity and loose cementation. At present, the operation of producing facilities in this oilfield is stable, and there are more than 20 wells that have been put into production, and the producing of crude oil output per day has exceeded more than 5,000 and the output of every well is fine. Since the offshore oilfield has the characteristics of the bigger porosity, the higher permeability, the more serious heterogeity and the higher crude oil viscosity. It will not only take more time, but also the recovery ratio will decrease if it carries on the early stage water-injection development like the oilfield on land. In order to curtail the oilfield development cycle and enhance the oilfield whole development effect, Tianjin Subsidiary company of CNOOC proposed that the test study of polymer flooding in early stage shoud be conducted in Lvda 10-1 Oilfield. Therefore, according to the geological characteristics and fluid property and the practical demanding of offshore oilfield, making use of the experimental method of indoor physical simulation,we do some researches on the feasibility of polymer flooding in early stage in Lvda 10-1 Oilfield. Under the 65℃condition, we do some tests on the viscosity property, flow property and adsorption characteristic test for several kind of polymer solutions that have been selected firstly. And we do some indoor flooding experiment for the polymer and cross-linked polymer system with good property that have been selected. The results show that the chemical flooding in early stage can not only shorten the oilfield development time, save operating cost, but also has a higher recovery efficiency than that of middle-late stage. The research results also indicate that, in the condition of same cost of chemical agent, the productive effect of the polymer gel flooding is better than that of polymer flooding. In the indoor research work foundation, Lvda 10-1 Oilfield implemented the test of single well polymer gel flooding. The data of field test indicated that, the early stage polymer gel flooding in Lvda 10-1 Oilfield has had the function of increasing oil and decreasing water, this has provided the basis for the large-scale promotion application of this technology.