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Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the cementing problem of long open hole malignant leakage wells, the thermo-sensitive shape memory loss prevention spacer and foam leakage prevention cement slurry were developed, which synergistically reduce the cementing loss risk of long open hole malignant leakage loss wells. The thermo-sensitive shape memory material was developed, which resistance temperature is 150 ℃ and deformation memory temperature is 80～110 ℃, the length of thermo-sensitive shape memory mesh particles after deformation is 10 times that of normal temperature, and the diameter of shape memory expansion ball after expansion is 3 times that of normal temperature. The thermo-sensitive leak-proof spacer was developed, and the bearing-capacity of 3mm crack can reach 8.5MPa. Foaming agent and foam stabilizer were selected, and foam cement slurry were developed, and the density can be adjusted from 1.12 to 1.31 g/cm3, the difference between the upper and lower parts was less than 0.01 g/cm3, and the compressive strength of 1.12 g/cm3 foamed cement stone can reach 6.6 MPa at 30 ℃/72 h, and bubbles in set cement are uniformly dispersed. The spacer duration design method that considering the equivalent plugging time and washing efficiency was established, and the foamed cement slurry section constant gas injection method was formed. Based on thermo-sensitive anti-leakage spacer and foam cement slurry, The leak-proof cementing technology has been applied for 2 Wells, and the one-time sealing section length exceeds 4000 m, and the spacer and cement slurry returned to the surface successfully and got good results. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study conducted C02-brine・rock reaction experiment to explore the influence of reaction on reservoir wettability, microscopic pore structure, movable fluid saturation, gas flooding effect and other four aspects・ The results show that C02 injection process, the reservoir wettability is like water wet, corrosion will happen at the same time, the recrystallization has been creating the phenomenon such as secondary minerals, resulting in micron grade dissolution pore and sub -micron and nanometer shouted congestion, ultimately affect the movable fluid can be gas injection reservoir development effect, the alkali feldspar in the reservoir and sialic acid salt content is relevant. This study has certain guiding significance for whether the reservoir is suitable for CO2 gas flooding. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The constant temperature adsorption of helium/supercritical CO2(SC-CO2) and deformation of coal are tested， the axial deformation and radial deformation of coal are real-time monitored， and the coal expansion deformation caused by effective stress and adsorption stress and the adsorption stress of coal to SC-CO2 are revealed. The results show that the axial strain by coal adsorption of different gases is higher than the radial strain， and the variation law of coal strain caused by helium and SC-CO2 with gas injection pressure is similar. In the process of increasing the temperature， the volume strain of coal adsorbed helium increased first and then decreased， while the volume strain of coal adsorbed SC-CO2 gradually decreased. With the increase of temperature， the deformation of coal during the adsorption of SC-CO2 gradually changed from the deformation caused by adsorption stress to the deformation caused by effective stress. The ratio of the volume strain of adsorption stress to the volume strain of effective stress is gradually decreased. The adsorption stress of coal to SC-CO2 decreases with the increase of temperature. When the temperature increases from 60℃ to 80℃， the adsorption stress only decreases by 29%. At the same time， the ratio of SC-CO2 adsorption stress to gas adsorption stress reaches the maximum at 60 ℃， and the SC-CO2 has the best gas displacement effect at this temperature. [ABSTRACT FROM AUTHOR]

The concept and connotation of microbial/chemical/gas flooding synergistic EOR technology are expounded from three aspects: material synergy, mechanism synergy and space-time synergy.The mechanism, characteristics and development status of microbial/chemical flooding synergistic oil displacement technology (microbial activated water flooding, microbial/chemical profile control, microbial/chemical flooding combined oil displacement） and microbial/gas flooding synergistic oil displacement technology (air assisted microbial oil displacement, microbial/CO2 synergistic oil displacement） are summarized, in the future, we will continue to explore the micro synergy mechanism, green and low-carbon technology, and expand the scope of application of the reservoir. [ABSTRACT FROM AUTHOR]

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to alleviate the problems of insufficient discharge distance of an environment -friendly cutter suction dredger with long pipeline transportation and difficulty of installation and maintenance and high using cost of traditional relay pumps in dredging in rivers, lakes and reservoirs, the experimental study on gas injection technology boosting discharge distance of pipeline transportation with two different gas injection methods of gas injection by jet pipe and direct gas injection by air compressor pipe with large diameter is carried out based on field dredging operations, and the effects of discharge distance increase and energy efficiency of the two gas injection methods are compared and analyzed. The results of study show that both gas injection by jet pipe and direct gas injection by air compressor pipe with large diameter have the effects of pressure increase, drag reduction, discharge distance increase and flow increase. Compared with the direct gas injection by air compressor pipe with large diameter, the gas injection method by jet pipe can better save energy, reduce cost and increase efficiency. Through field tests and compared with the traditional relay pumping method, the adoption of gas injection by jet pipe method can increase production by about 9% and reduce the dredging cost per cubic meter by about 6.0%. If converted into discharge distance, the discharge distance of pipeline transportation can be increased by about 16.6% on the basis of the original discharge distance, which has remarkable effects of energy conservation and discharge distance increase. The results of this study can provide reference for long distance discharge operations of environment -friendly cutter suction dredgers in dredging in rivers, lakes and reservoirs. [ABSTRACT FROM AUTHOR]

CO2 Flooding has been widely used in the petroleum industry for decades, especially in light-medium reservoirs near late maturity. The injected fluid is prone to fingering and severe gas channeling in the fracture network in many CO2-E0R reservoirs because of low permeability and high heterogeneity. The intelligent plugging agent based on non-covalent interaction has strong plugging ability and good injectivity, and is effective in controlling gas channeling and improving oil recovery in auxiliary CO2 flooding. The research progress of intelligent channeling plugging agent used to assist CO2 flooding is reviewed, and the molecular composition, mechanism and performance of CO2 responsive channeling plugging agent are analyzed, and its future development trend and application prospect are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the fractal characteristics of fractured medium in gas reservoirs and the effects of reservoir operating pressure changes on gas reservoir stability, the fractal dimension was introduced to improve the gas-water relative seepage model in the reservoir fracture and pore system. The gas injection and extraction seepage process in fractured reservoirs was simulated based on the finite element software COMSOL, and the effects of gas content saturation, fractal dimension and fracture size ratio on the bottom well pressure in gas reservoirs were researched. The results show that the fractal dimension in the reservoir medium has an opposite effect on the relative permeability of gas and water phases, and there is a negative correlation between the reservoir operating pressure and the fractal dimension of the fractured medium. The adopted calculation model takes into account the fractal characteristics of the fractured reservoir and the gas-water boundary conditions, and the calculation accuracy is improved by 3%. [ABSTRACT FROM AUTHOR]

By introducing the natural gas generation system into the foam flooding system, they react with each other, release heat, and generate a large amount of gas.The gas interacts with the foaming agent to generate a large number of fine foams, “blocking big but not small”,inducing non-producing reservoirs, promoting the oil layer is fluidly connected to improve oil and gas recovery and solve the problem of poor displacement effect caused by rapid water cut rise.The preferred self-generating formula is: 2.5% sodium nitrite+2.5% ammonium chloride+3.0% citric acid+1% pH regulator.The preferred foam system is: 0.5% cocamidopropyl betaine+0.1% partially hydrolyzed polyacrylamide, stirring for 1 min at 5 000 r/min, the foam foaming volume is 430 mL,the liquid elution half-life is 120 s, and the defoaming half-life is 500 s.The self-generating foam flooding system can automatically generate bubbles to supplement the formation energy, without the need for special foaming equipment, and it is easy to use on site.200 mL of foam liquid can generate about 830 mL of foam within 15 s, the liquid elution half-life is 122 s, and the defoaming half-life is 494 s, which can fully meet the field requirements, especially suitable for oil displacement in formations with high water content, heterogeneity and low formation pressure. [ABSTRACT FROM AUTHOR]

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, a large number of light oil and gas reservoirs have been discovered in the paleogene sand sub-section of the northern belt of the Dongying Sag, and their oil and gas phase characteristics and reservoir formation patterns still lack in-depth understanding. Through the study of oil and gas geochemistry, fluid inclusion, and burial history-thermal evolution history, combined with crude oil cracking experimental products and oil and gas PPT simulation in the deep reservoir of the four lower sub-sections of sand, the deep oil and gas genesis, phase evolution and reservoir formation mode in this area are discussed. The results show that with the increase of the degree of cracking of crude oil, the critical condensation temperature gradually decreases. At higher pressures (20 MPa), the cleavage of the heavy hydrocarbon gas group was inhibited, the molar fraction of methane in the fluid composition decreased, and the critical condensation pressure of the fluid envelope decreased with nonlinear fluctuations. The characteristics of natural gas composition and carbon isotope show that the mirror plastoid reflectivity (R) of natural gas maturity parameter is between 0.9% and 1.5%, and the natural gas samples detected are the mixed causes of crude oil cracking gas and kerogen degradation gas. The absolute content of amantane and steroid detected in crude oil indicates that the deep crude oil samples detected are in a highly mature state, but are still in the early stages of cracking, and the crude oil cracking gas is moved upwards by the off-site crude oil cracking of the deep depression. The simulation of burial history, thermal evolution history and the uniform temperature of fluid inclusions in the reservoir show that there are mainly two stages of oil and gas injection in the sub-reservoir of the FS2 wellsha four sub-sections, namely crude oil (including kerogen degradation gas) charge at the end of the sand three-stage sedimentation stage and crude oil cracking gas injection from the deep reservoir in the early sedimentation of the Minghua Formation. Late high-maturity crude oil crack gas filling caused evaporative fractionation and gas washing, which was an important reason for the formation of deep light reservoirs in the region, and eventually secondary unsaturated condensate gas reservoirs and volatile reservoirs were formed [ABSTRACT FROM AUTHOR]

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The interior of the molten pool is a complex high temperature environment, and the internal high temperature flue gas flow process has an important impact on the smelting effect Aiming at the flow process of high temperature flue gas in the molten pool, the growth of bubbles generated by high temperature flue gas injection, the change of velocity in the rising process and the change of temperature in the molten pool, as well as the gas liquid two phase mixing state in the molten pool during continuous injection at different speeds were analyzed by numerical simulation. The results show that the bubbles generated by high temperature flue gas injection grow larger at the nozzle of the spray gun, the initial shape is semi circular and gradually becomes elliptical. It rises close to both sides of the spray gun pipe wall. During the rising process, the lower boundary is concave inward and rises in an 11 umbrella cap shape11. The higher the rising height is, the deeper the inward depression is, and it breaks into multiple small bubbles when it rushes out of the liquid level. The velocity of high temperature flue gas with different injection speeds decreases rapidly in the process of generating bubbles at the nozzle of the spray gun. The velocity of the generated bubbles is basically stable at 0.25 m/s. When the bubbles move in the molten pool, their internal temperature drops rapidly to 300 K in a short time, and there is an obvious gradient change in the internal temperature field. Within 1 s, the higher the injection speed of high temperature flue gas, the better the gas liquid two phase mixing state in the molten pool. [ABSTRACT FROM AUTHOR]

Objective This paper aims to solve the problem of asphaltene deposition blocking wellbore in the process of gas injection production of crude oil in Donghe block. Methods Based on light scattering theories and using a high pressure/high temperature solid deposition test device, the effects of temperature, pressure, gas-oil ratio and other factors on the precipitation behavior of asphaltenes were tested. Results Temperature increase improves the solubility of the asphaltene in the crude oil and promotes the stability of the crude oil. Cnder isothermal pressure depletion conditions, asphaltenes gradually precipitate and reach maximum precipitation near the bubble point pressure with the descend of pressure. In other words, the risk of asphaltene deposit ion is highest when near the bubble point pressure. The bubble point pressure of DH-1 well corresponds to the >veil depth of 2 HO m, which is close to the actual blocked position at 1 969 min production >veil. Therefore, the bubble point pressure can be used to predict the plugging location in oil wells. The higher the amount of dissolved gas, the higher the onset asphaltene precipitation pressure, and thus the larger the asphaltene precipitation pressure range the more likely asphaltene deposits to occur in deeper well sections. Conclusion The research reveals the asphaltene precipitation law during gas injection, which has an important guiding role in prevention and control of asphaltene precipitation in gas injection wells. [ABSTRACT FROM AUTHOR]

Based on the characteristics of multiphase flow in riser annulus during dual-gradient drilling with riser gas injection, a multi-phase flow model for the riser gas injection dual-gradient drilling wellbore was established. The model was solved with the finite difference method and combined with the actual parameters of a deep water well in the Gulf of Mexico. The influences of drilling parameters on the bottom hole pressure and the annulus pressure, and the influence factors on the gas injection flow rate were discussed. The research results show that, the bottom hole pressure of dual-gradient riser gas injection drilling is lower than that of conventional drilling, and is more suitable for subsea narrow-density window drilling; the magnitude of the gas injection flow rate during the dual-gradient riser gas injection drilling process has great effects on the bottom hole pressure and the annulus pressure, and the water depth as well as the drilling fluid density are 2 important factors influencing the gas injection flow. In the design of the dual-gradient drilling parameters for riser gas injection, the appropriate gas injection flow rate should be selected and the drilling fluid density should not be too large to ensure the safety of dual-gradient riser gas injection drilling. The research has guiding significance for the design of dual-gradient drilling with riser gas injection and field operations. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)