化工科技论文写作学院：提高采收率研究院姓名： 李 浩 学号： 2015210502指导教师：郭爱军任课教师：袁珮Aquifer Deep Diversion Agent for Deep Reservoir Conformance ControlHao Li1, Chuanrui Yu2, Aijun Guo2The building of chemical engineering1China University of Petroleum(Huadong)Huangdao, Qingdao, 26655, ChinaEmail:504112010qq.comPhone number:18811152033* Correspond author.AbstractPremature water encroachment or early water breakthrough is a common problem in the industry. Ever increasing water cut will reduce oil recovery, decrease wells productivity and increase the cost of produced water handling. Conventionally the only solution to tackle aquifer dominant encroachment is to introduce a water shut-off chemical in the producer to stop water from coming in. In this paper a novel deep reservoir conformance control technology for aquifer is studied. The main characteristic of the chemical used in this technology is its ability to propogate deep into the reservoir for effective blockage and diversion of aquifer channels without the risk of near wellbore blockage. Aquifer Deep Diversion Agent (ADDA) is a form of solution with viscosity similar to water and is only soluble in the water phase. It aggregates once it contacts with high salinity aquifer water and is absorbed on water wet rock to form a microscopic blockage which creates diversion. Its strong adsorption on the rock surface will ensure strong and stable blockage. Its fail safe mechanism includes its inability to absorb on oil wet rock and it does not aggregate whenit contacts with oil thus it will not impair the performance of oil bearing zones and the oil inflow performance. Unlike other technologies, ADDA is tailored according to the reservoir properties and particularly aquifer salinity. The size of molecular aggregation and its rate of aggregation can be designed in the lab based on specific ion composition in aquifer water.Key word: ADDA, aquifer, deep diversion, reservoir conformance, microscopic blokage.IntroductionProduced water is a by-product of the production of oil and gas from underground reservoir. It is estimated are in the order of 250 million barrels in 2007, for water-to-oil ratio 3:1, and are expected to increase more than 300 million barrels per day between 2010 and 2014 (Fig. 1, Dal Ferro and Smith 2007). Water handling costs are high, every year more than $40 billion is spent dealing with it (Bailey, 2000). Excessive production cost associated with water production had cause the economic live of many wells to be shortened. These expenses include lifting, handling, separation, and disposal. The unwanted water uses up the natural drive and leads to possible abandonment of the production well. Furthermore, excessive water increases the risk of formation damage, produces a higher corrosion rate, and increases emulsion tendencies. It may also form a hydrate because the water and gas are not produced in a proper ratio. Figure 1- Global onshore and offshore water production (Dal Feero and Smith 2007)Numerous technologies have been developed to tackle unwanted water production. In order to design an effective well treatment, the nature or the water sources must be known. Thare are a few mechanisms whereby water can arrive at a production well as the following; (a) water conning, (b) rise of water oil contact, (c) through a high permeability layer, (d) through one or more fractures that connect the aquifer to the well as shown in Figures 2,3,4 and 5 (Moawad, 2004).Figure 2 : Water ConingFigure 3: Depletion of reservoir pressure causes an increaseon water oil contactFigure 4 : Water arrives through high permeability layerFigure 5: Water arrives through one or more fractures thatconnect the aquifer with the wellIn this work a new deep reservoir conformance control technology for aquifers was studied. In order to Base oil-watercontactDepleted waterWellWellWellWellOilOilOilWaterHigh permeability channelWaterOilFractureWateravoid blocking the aquifer near to the producer and in order to inject chemicals deep into the reservoir a water like low viscosity chemical - Aquifer Deep Diversion Agent (ADDA) was used. The chemical prepared with low salinity water can be injected into water path of core or reservoir easily. When the chemical is actived by the ions in the higher salinity aquifer water the chemical is aggregated and blocks the water path. Therefore, aquifer water can be diverted into low permeability zones resulting in an increase in production ofbypassed oil and a decrease of water cut.MthodProperties of aquifer deep diversion agentDeep propagation enables aquifer blocking at the source Aquifer or injected water prefers to flow in the high permeability and low oil saturation zones, and will normally bypass low permeability zone with high oil saturation. ADDA provides a unique solution that is able to tackle both aquifer and injector water ingress at the source by injecting in the producer. When this water-like low viscosity chemical solution is injected in