Advanced Materials Research Vols. 962-965

Abstract: In order to improve the flowability of crude oil, heavy oil reservoir usually developed by steam injection. While this process produces a lot of greenhouse gases. To deep reservoir, heat loss in the wellbore tends to more severe and thermal efficiency is lower. In-situ Combustion (ISC) is featured by heavy components’ combustion, high thermal efficiency and high oil recovery. Those advantages are outstanding especially in the aspects of improving thermal efficiency and reducing greenhouse gas emissions. This paper researched on ISC EOR process in a complex fault block, including reservoir design and performance evaluation. Remarkable development results have been achieved, which shows the potential for ISC technology and this paper provides a reference for the development of similar reservoirs.

Abstract: There was carbon dioxide (CO₂), hydrogen sulfide (H₂S) and other corrosive media in underground gas storage. As injection-production running, the injection and production string suffered corrosion. The wall of string might be thinner and be perforated. The well safety was influenced, and even the gas storage. How to choose reasonable and efficient anti-corrosion material was an important problem. According to Su 4 underground gas storage actual injection-production condition and the corrosion environment, the software simulation and laboratory experiments have been done. The material of injection-production string optimization was optimized, based on the evaluation of corrosion rate and the two aspects of sulfide stress cracking resistance. The results showed that the imported super 13Cr (S13Cr) could meet demand. It could ensure that the string corrosion rate was smaller than 0.125 mm/a and there was no pitting corrosion. When the tpemerature was at 135℃, only the S13Cr corrosion passivation membrane was not been damaged. And the sulfide stress cracking (SSC) would not occur. The S13Cr is recoomneded Su 4 underground gas storage.

Abstract: In this paper, the model of low temperature fractionation CO₂ capturing process is established with HYSYS to carry out the simulation of the process. According to the simulation results, it is concluded that as the CO₂ content in the feed gas raises, the CO₂ product purity increases and the cooling energy cost of the system decreases. As the CO₂ product purity rises, the cooling energy cost increases more and more rapidly. According to the 91.0% CO₂ content feed gas, the optimized fractionation pressure is 3.1MPa and the corresponding liquefaction temperature and condensing temperature is-20°C and-24°C respectively.

Abstract: Carbon dioxide miscible flooding in oil reservoirs is a general method of enhancing oil recovery, nevertheless, not all reservoirs adapt to this method. Therefore, evaluating the adaptability of carbon dioxide flooding reservoirs becomes an important problem which is urged to be solved. Through the research of carbon dioxide flooding situation and displacement mechanism, twelve factors which influenced the oil displacement effect could be obtained. Compared factors with oil recovery by means of the advanced analysis of SPSS, and chose ten factors to be the evaluating indices which could apply in cluster analysis. Through building mathematical model and clustering reservoirs, the adaptability of carbon dioxide flooding could be evaluated comprehensively. Apply this method to cluster nine typical reservoirs which have adopted carbon dioxide flooding, the results show that, this method can evaluate the adaptability of carbon dioxide flooding reservoirs, which is corresponding to the real exploitation effect.

Abstract: In the later waterflooding sandstone reservoir, there are many serious development contradictions, especially in the aspects of water breakthrough and heterogeneous development. Based on the laboratory experiments, numerical simulation research on historical match of the low temperature oxidation kinetics model, the injection mode, foaming agent concentration, gas to liquid ratio, steam injection rate and other key parameters of air-foam flooding were carried out. The results show that, air foam flooding technology integrated comprehensive effect of low-temperature oxidation, air flooding and foam flooding, which enhance oil recovery nearly 8% by block the thief layer effectively and improving the swept volume. Air-foam flooding technology also can reduce the amount of water injection and water production, which improved the utilization rate of water resources and reduced output liquid processing cost. This technology shows its broad prospect of application and can provide reference for similar reservoirs.

Abstract: The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then they stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. In this paper, according to the characteristic of the gas drilling technology, we optimized the scheme of freezing technology for borehole stability to give the theoretical basis of the industrial application.

Abstract: Block 127 reservoir was a typical heavy oil reservoir with normal pressure system, high density and viscosity. The block was low production because formation water invaded seriously. Well condition and effects of measure were badly year after year. In order to clarify remaining oil distribution rule, east and west typical well group of block in 127 was chosen. Careful research in typical well group and multiple well group synthesis research method was used to research with numerical simulation method. The sub-zone sand body residual oil saturation chorizo-gram of well groups and entire block were mapped, qualitative and quantity analysis residual oil distribution rule was studied on plane and vertical. The larger and more complex structure reservoir, used to Domain decomposition method with the typical well group fine research, multi-well-group integrated research method is feasible. The knowledge of residual oil is made deeply and these works offer technique support for block heavy oil reservoir.

Abstract: In order to develop small-scale natural gas liquefaction equipment, a small expansion natural gas liquefaction process was designed, which was based on the technical parameters of the single screw compressor and expander developed by Beijing University of Technology. The effect of the key parameters on the natural gas liquefaction rate and specific power consumption was simulated and optimized. The results showed that the liquefaction rate of the process can reach 100% and the specific power consumption was relatively low under the optimal operation conditions. These research results can provide theoretical basis for the design of small-scale natural gas liquefaction equipment.

Abstract: Through the flat 53-13 well group oil and gas mixed transportation test, the gathering radius increases from 3Km to 5km, to realize the full closed gathering. Reducing electricity consumption, according to the existing problems in the mixed transportation technology are discussed, for intermittent oil and high gas oil ratio well area, a station for reference.

Abstract: In order to study the influence of horizontal well with chemical flooding on remaining oil of side interlayer after polymer flooding, experiments about high concentration polymer flooding, polymer activator alternating flooding and variable concentration polymer flooding are completed, after determining optimum position of horizontal well and the way of injection and production of water flooding and polymer flooding. Results show that the three methods all can improve recovery efficiency of side interlayer after polymer flooding effectively; horizontal well with variable concentration polymer flooding compared with high concentration polymer flooding, the improved recovery efficiency difference is small because of the same polymer total amount; horizontal well with polymer activator alternating flooding can not only enlarge sweep volume, but also improve the efficiency of wash oil, enhance recovery efficiency obviously, when compared with high concentration polymer flooding, is the best method for remaining oil of side interlayer after polymer flooding.