| With the development of clastic reservoirs in Tahe Oilfield,the problem of high water cut in oil wells is becoming more and more serious.By the end of 2016,the number of high water cut wells(water cut(>80%)reached 165,accounting for 54%of the total number of wells opened.Water shutoff is an effective means of water control in high water cut oil wells,and gradually becomes the dominant water shutoff technology.However,with the increase of water shutoff cycles,the single water shutoff method can not meet the need of tapping the remaining oil around the wells of bottom water reservoirs,so it is urgent to carry out the research and field application of compound water shutoff technology.In view of the above problems,the following work has been carried out:(1)Based on the analysis of reservoir characteristics and development status,it is clear that the Tahe area belongs to the edge-bottom water reservoir,and the reservoir heterogeneity is poor,and the bottom-bottom water is active.Based on the remaining oil distribution experiment,the bottom of the Tahe area is obtained.The water rushes along the high-permeability strip,and the remaining oil is mainly the remaining oil between the small-pore and low-permeability areas,and the local enrichment and overall dispersion are mainly in the high-permeability area of the large pores;(2)Based on the optimization experiments of high-efficiency new polymers and cross-linking agents,AMS-2 polymer is determined to be a highly efficient new polymer,and(AMS-A,AMS-B)cross-linking agent is a crosslinking agent for AMS-2 polymer jelly system;The optimization study of the formulation of temperature and salt-resistant jelly system was carried out,and the performance of temperature and salt-resistant gel was evaluated based on microscopic morphology and plugging rate;(3)Six kinds of better surfactants were preferably obtained from 18 kinds of surfactants from the surface tension and superior performance;the temperature resistance of the six selected surface activities,the adsorption of the rock to the surfactant,and the surface were evaluated and analyzed.Salt tolerance,interfacial tension and temperature stability of the active agent,surfactant foaming and surfactant emulsifying ability,and compounding 6 kinds of selective surfactants;(4)An indoor experimental device for compound water blocking and synergistic technology was established,and a single-gel and jelly-surfactant compound synergistic technology experiment was carried out.The experiment was compared with the surfactant-gel composite water-blocking method.The recovery factor of the method;based on the improvement of the experimental scheme,the sequential influence experiment of the injection gel and the surfactant was carried out;the experimental device for visualizing the acrylic glass plate was established,and the water was blocked by a single jelly,the gel and the surfactant were blocked.A simulation experiment was conducted;(5)Taking the TK111H well as an example,the design of the combined water control and efficiency improvement program was carried out,and the on-site test was carried out.The results show that after the implementation of the process,the daily oil increase is 22.8 tons,the cumulative oil increase is 4166 tons,the oil cost per ton is 155 yuan,and the input-output ratio Up to 8.18,and continue to be effective. |
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