Plugging Agent Choice And Effect Assessment In High Water Cut Period

Plugging agent choice first is blocking agent types of choice, the choice of plugging types main consideration plugging agent and the compatibility of the strata sex, including blocking agent and pore throat size formation of relations, plugging the chemistry of the reservoir water salinity and the relationship between the thermal stability, plugging the strata of the relationship between temperature and plugging agent of acid and alkaline PH value and formation of the relationship is the most important filter conditions. In one of a large number of water shutoff profile control agent is HeMou reservoir characteristics of the selected plugging agent, this requires a lot of material and time, so it will commonly used the profile control agent performance parameters of the establishment of database, and then will the actual blocks of characteristic parameters and profile control agent, the library to optimal matching profile control agent XuanDiao type.The selection process, the first according to blocking agent with formation of pore throat size the matching relation between from blocking agent in the preliminary database to choose the appropriate plugging agent, then reuse plugging agent the chemistry of the reservoir water salinity and the matching relation, plugging agent thermal stability and formation of the matching relation between temperature and plugging agent of acid and alkaline PH value and formation of the matching relation between further optimization plugging agent, finally choose the can and formation of pore throat matching, and can match with formation salinity, temperature and strata formation matching PH value of matching the best plugging agent.Modern reservoir engineering research shows that, in the oilfield water flooding process, the reservoir heterogeneity influence, usually, injection water always preferred a loose high along the cementing reservoirs period of seepage, once the injection water reservoirs formed in high for breakthrough, it will further reduce trational resistance, water seepage speed will be further speed up. In the injected water long-term blunt rinse, part of the shale content will be cemented disintegrating dissection, to increase the seepage channel, form secondary throats, make the reservoir of oil and water sports in contradiction dramatically worse, reservoir development to bring adverse impact. Through the water shutoff profile control, can be blocked high for reservoirs, reduce the invalid injection, improve carry water rate, change of flow direction, improve the injection water sweep volume and oil displacement efficiency, improve the recovery.For plugging agent choice effect evaluation can according to some evaluation index to make judgment. Water plugging effect evaluation index have before and after water injection pressure, water Wells, note water, start-up pressure, depending on the bibulous index, PI value, bibulous the change. Water plugging effect by oil well before and after water content, intense, and decline rate of the change of the values.HeNan oilfield water flooding oil field is the old, formation heterogeneity is serious, according to statistics, rare oil well comprehensive water cut to89.39%, with double the oilfield already was as high as90.59%, the water flood effect is getting worse. Chemical water is late stable development crude oil one of important stimulation measures. HeNan oilfield of the technology of chemical water for more than15years, developed a variety of plugging agent and profile control agent tone. HeNan oilfield into high water cut after1, because the vertical distribution of oil well long, layer number, more oil layer upon layer of the contradiction between intensifies, main reservoir and the main oil production capacity gap is big; Plus sand body sedimentation range size is differ, cause oil water interface is uneven, the oil group, each with different small layers oil water interface, plane stagger distance is bigger. In oilfield development process, the geological characteristics of the distribution of the oil and water caused underground complex situation, worsen the contradiction between layers of the reservoir; And the single well more injection-production oil production, serious interference between layer, so that the high water cut, low energy, low permeability of reservoir has been producing extent is low.