Advanced Materials Research Vols. 734-737

Abstract: In order to overcome the disadvantages of rapid acid-rock reaction rate, short penetration distance, and poor acidification results exist in the process of traditional acidification in Qijiabei oil field, this paper has developed research on retarded acidification technique and optimized its formula and injection parameters. With the operations of complex formulation, screening and optimization among main agent, scale-froming ion inhibitor, permeability-increasing agent、clay stabilizer、corrosion inhibitor、retardant, a kind of retarded unplugging formula with good combination property suits for environment of high temperature has been developed. According to research, this developed formula system has permeability improving rate of 20.5% on natural core, suggest good characteristics of corrosion inhibition, retardation and permeability increasing.

Abstract: CO₂ corrosion is the main safety problem of production process in gathering, delivering and treating of oil and gas. Injecting inhibitors to suppress CO₂ corrosion in oil and gas fields is an easy-to-use, low investment, quick solution method. The goal of this study is to summarize the already established research results of controlling CO₂ corrosion, inhibition mechanism of CO₂ corrosion inhibitors is reviewed, application status of inhibitor technology in CO₂ corrosive environment is discussed. Research status of amides, imidazoline derivatives, quatemary ammonium salts and schiff bases overseas and domestic is highlighted. Finally, an outlook on the development trend of CO₂ corrosion inhibitors is presented.

Abstract: The exploitation of heavy oil and bitumen attracts more and more attention. Compared with normal light oil, heavy oil is of characteristics as high viscosity, low mobility and difficult for exploitation as a result of higher requirement of mining. The developing mechanism and process of SAGD is introduced in this paper. Some front technologies on the basis of SAGD are described about their application prospect as well. It is also summarized about SAGD development together with implementation in the field through detailed investigation of SAGD technology from home and abroad. Meanwhile, the main problems of SAGD facing to researchers are also summarized as well as the presentation of the corresponding improvement measures.

Abstract: Recently,accelerating shale gas development and utilization is of great significance to safeguard the security of energy supply. As a new energy resource, shale gas has great development prospects, but to develop and to make use of this resource is quite difficult and has high risks due to the exploitation technology, environmental protection, the market, and so forth. It can help the shale gas companies get better development by focusing on the prospective risks that they may face and looking for the solutions. This paper analyzes the various risks that the shale gas development companies may face and puts forward the measurements to deal with these risks.

Abstract: This paper analyzed the balanced flood performance of various layers and the remaining oil distribution through numerical simulation technique. It shows that, the main remaining oil type of intended layers is caused by voidage-injection imperfection. Considering the needs of the follow-up infill well pattern and tertiary oil recovery, we decide to maintain the relative independence and integrity of each well network without disturbing the pattern configuration and the mining exploit object of various sets of well pattern. Finally we confirm to perforate adding the first infill wells of intended layers to consummate the water flooding regime. Through analyzing the production target of different well pattern optimization programs relatively, it shows that the best program has regular well pattern and large drilled thickness.

Abstract: It is quite difficult for reservoir exploitation with worse barrier zone, especially in thin pay-zone, limiting hydraulic fracture height propagation. This paper described the theory of controlling the fracture height by creating artificial barrier, and net pressure distribution in the crack was determined by assuming the artificial barrier is with stress gradient. Then, stress intensity factors in the crack tip were gotten on the basis of fracture mechanics theory, and fracture propagation model was established in accordance with fracture criteria of tensile open crack. The established model also described the action of treatment pressure on the fracture height and influence of artificial barrier on the fracture height propagation. By contrasting the results, it is feasible for artificial barrier to limit the fracture height propagation, and this model also can be used in hydraulic fracturing design in the oilfield.

Abstract: Henan Oilfield Xiaermen Qianbei block is the medium-deep heavy oil reservoir. Due to the high viscosity of crude oil, formation cementation loose, sand production and reservoir water-sensitive, the pre-trial is less effective. The problem is the inefficiency of steam injection, poor oil-steam ratio, sand production serious, the poor pump efficiency and the abnormal productions. It is important to improve the mobility of heavy oil in the formation and wellbore for the development. According to the reservoir characteristics and the experience of the primary development, the measures which include the high-pressure gravel packing sand control, insulated tubing of steam injection, anti-swelling agent reservoir protection, formation and wellbore viscosity reducer and rod sucker-rod pumping system are carried out in a pilot test of the four wells. After the pilot test, the oil-steam ratio increases from 0.08 to 0.55, the average daily oil production increases from 0.5 tons to 8.0 tons. The pilot test has achieved great success and promoted the application in medium-deep heavy oil thermal recovery in the entire block, simultaneously provided the basis for the efficient development of other similar blocks.

Abstract: Nanometer microspheres injection is a new deep profile control technology. Nanometer microspheres could inflate with water, resulting in plugging step by step in reservoirs, which could improve the swept efficiency in the reservoir and enhance oil recovery. By using non-homogeneous rectangular core, oil displacement efficiency experiment was conducted for studying the influence of different injection methods on the effect of injection nanometer microspheres. The experimental result shows that, compared with development effect of single-slug injection or triple-slug injection, the one of double-slug injection is better. Nanometer microspheres can enhance oil recovery significantly in medium and low permeability reservoir.

Abstract: In order to improve the pump efficiency of pumping wells, by means of the basic formula of pump efficiency, the mathematical model and boundary conditions of dynamic control chart is obtained, and the pump efficiency of pumping wells is drawn. Analysis shown that the pump efficiency is sensitive to the water content and pump leak rate. The higher the water content is, the higher pump efficiency is. The pump efficiency will be reduced with the increasing of pump leak rate. The dynamic control chart of class II block of A oilfield is given in the paper. After taking the measures, the pump efficiency of pumping wells is obviously improved. The dynamic control chart drawn by this method can provide a scientific basis for improving the pump efficiency of pumping wells in oilfield.

Abstract: Conventional reservoirs and unconventional reservoirs differ a lot in terms of accumulation mechanism, distribution, exploration evaluation method and technique. Therefore the accumulation study and exploration evaluation for unconventional reservoir are different from that of traditional reservoir. This paper presents five development techniques of unconventional oil and gas resources, their features, advantages and disadvantages and summarizes the current advanced technologies and their development trends.