Fracturing Technique Study Of Internal Controlling Water To Improve Recovery Efficiency At High Water-bearing Thick Beds

At present, a lot of oilfields on the world enter the mature productive life. As the oil is the non-renewable mineral resources for excavation, how to get more petroleum resources to the greatest extent will play an important role in world economic continued development. Therefore, the technique to improve recovery efficiency has an extensive attention worldwide.To further excavation petroleum resources, study and test to improve recovery efficiency technique have developed enthusiastically at home and abroad in recent years. They are polymer flooding technique, polyatomic flooding technique, miscible flooding technique, deep profile control technique and so on. These techniques got good applied results. To get better results, we work hard to explore the invention and discovery in principle in order to further improve recovery efficiency and benefit of methods.Thick bed is the main oil reservoir of developing Daqing oilfield which contains over 60% resources all over the field. The oilfield has developed for many years, but it has a lot of non-producing remaining reserves to have extensive excavation potential. Therefore, according to the situation of developing thick beds now, the technical study should be worked hard to effectively control water cut and to improve recovery efficiency, its significance being great. Since the oilfield entered the high water cut stage, water-bearing speed was very fast and the water cut high. The overall water cut of the whole field reached 87% at the end of 2000. The water cut of main reservoir produced by basic well networks reached 90~95%, the production cost increased year by year. Therefore, according to the development of thick beds with high water cut and the production characteristics of oil wells at high water cut stage, we present the well stimulation to improve recovery efficiency, that is to say, we developed the relative permeability modifiers (RPM) and used the corresponding technologies to complete the result of the disproportionate permeability reduction (DPR) in the oil reservoir, controlling the water cut increase of oil wells and prolonging the production life. The object of improving recovery efficiency and increasing production of thick beds with high water cut were obtained by changing the flow water-oil ratio (WOR) in the formation to improve the water saturation in the oil reservoir.The main research contents and new ideas are as follows:⑴Creativity presents the technical principle of using the relative permeability modifiers (RPM) to improve recovery efficiency. The relative permeability modifiers (RPM) are composed of high molecular polymer or weak cross-linked gel. It is mainly used to plug water selectively. The paper studied and considered that RPM has the characteristic of DPR to change oil-water mobility ratio. Therefore, the water saturation should rise and the oil saturation should drop in the operational zone and the extent of action effect to improve the microscopic oil displacement efficiency. At the same time, RPM also has the action of driving oil and changing swept volume, or it has many action mechanisms to reach the object of improving recovery efficiency to the greatest extent.⑵RPM was developed firstly at home with the aim of controlling water cut and improving recovery efficiency.On the basis of using the literature for reference, RPM system was developed. The characteristics of RPM...