Most of the oil wells enter the middle and late stages of extraction. After one oil extraction, water injection is needed for secondary extraction. With a large amount of calcium and magnesium ions in the water, which...Most of the oil wells enter the middle and late stages of extraction. After one oil extraction, water injection is needed for secondary extraction. With a large amount of calcium and magnesium ions in the water, which is easy to form a large amount of insoluble scale, its formed barium sulfate and strontium sulfate scale are more difficult to handle than carbonate scale. In order to reduce the difficulty of oil production work, this paper mainly targeted the sulfate scale for experiments, and prepared the scale retardant agent CQC-1. Through orthogonal experimental screening, the mass ratio of itaconate acid:methacrylic acid:AMPS:sodium acrylic sulfonate was 2:1:1:1, increase the amount of evocating agent was 8% and the reaction time was 4h, the sulfate scale inhibitor synthesized at the temperature of 80°C had the best performance. Using scale resistance rate, degradation and salt-resistance, the experimental results showed that the scale resistance rate of CQC-1 reached 90.46%. In the four-week degradation experiment, the degradation rate reached over 71% and was maintained by 80.65% at 150°C, while the scale resistance rate still reached 80.35% in simulated saline. It has excellent scale resistance, temperature resistance, salt-resistance and degradation, and has good development prospects.展开更多
In view of the shortcomings of poor temperature resistance, poor pumpability and poor pressure-bearing capacity of commonly used gel plugging materials, polyacrylamide (HPAM) and N,N-methylene bisacrylamide (BIS) were...In view of the shortcomings of poor temperature resistance, poor pumpability and poor pressure-bearing capacity of commonly used gel plugging materials, polyacrylamide (HPAM) and N,N-methylene bisacrylamide (BIS) were selected for crosslinking and compounding to make a new type of gel plugging material with high temperature and pressure resistance. The compressive strength and yield stress were measured by inverted observation method to evaluate the gel strength. The anti-temperature, anti-pressure, anti-dilution and gel-breaking properties of the gel were evaluated. Finally, 71 type high temperature and high pressure water loss instrument and high temperature and high pressure filter with slit plate were used to evaluate the plugging capacity of gel plugging agent. The experimental results show that the new gel plugging system between 100°C - 120°C, gelation time can be controlled at about 5 h;it has strong temperature resistance, compression resistance, dilution resistance and gel breaking performance. In the face of permeability and fracture leakage simulation experiments, when the ambient temperature below 120°C, pressure within 5 MPa, the filter loss of gel plugging agent is far less than the market two conventional plugging agent, has excellent plugging performance.展开更多
In complex strata, oil-based drilling fluid is the preferred drilling fluid system, but its preparation cost is high, and there are hidden safety risks. Therefore, the new progress of high-performance anti-collapse wa...In complex strata, oil-based drilling fluid is the preferred drilling fluid system, but its preparation cost is high, and there are hidden safety risks. Therefore, the new progress of high-performance anti-collapse water-based drilling fluid at home and abroad is analyzed. It is difficult to prevent and control the well collapse. Once the well wall instability problem occurs, it will often bring huge economic losses to the enterprises, and the underground safety accidents will occur. In order to ensure the stability of the well wall and improve the downhole safety, the key treatment agent of water-based collapse drilling fluid is selected, the anti-collapse drilling fluid system is formulated, the evaluation method of drilling fluid prevention performance is established, and a set of water-based drilling fluid system suitable for easy to collapse strata in China is selected to ensure the downhole safety. The development trend of high performance anti-collapse water-based drilling fluid is expected to provide a reference for the research of high performance anti-collapse water-based drilling fluid system and key treatment agent.展开更多
文摘Most of the oil wells enter the middle and late stages of extraction. After one oil extraction, water injection is needed for secondary extraction. With a large amount of calcium and magnesium ions in the water, which is easy to form a large amount of insoluble scale, its formed barium sulfate and strontium sulfate scale are more difficult to handle than carbonate scale. In order to reduce the difficulty of oil production work, this paper mainly targeted the sulfate scale for experiments, and prepared the scale retardant agent CQC-1. Through orthogonal experimental screening, the mass ratio of itaconate acid:methacrylic acid:AMPS:sodium acrylic sulfonate was 2:1:1:1, increase the amount of evocating agent was 8% and the reaction time was 4h, the sulfate scale inhibitor synthesized at the temperature of 80°C had the best performance. Using scale resistance rate, degradation and salt-resistance, the experimental results showed that the scale resistance rate of CQC-1 reached 90.46%. In the four-week degradation experiment, the degradation rate reached over 71% and was maintained by 80.65% at 150°C, while the scale resistance rate still reached 80.35% in simulated saline. It has excellent scale resistance, temperature resistance, salt-resistance and degradation, and has good development prospects.
文摘In view of the shortcomings of poor temperature resistance, poor pumpability and poor pressure-bearing capacity of commonly used gel plugging materials, polyacrylamide (HPAM) and N,N-methylene bisacrylamide (BIS) were selected for crosslinking and compounding to make a new type of gel plugging material with high temperature and pressure resistance. The compressive strength and yield stress were measured by inverted observation method to evaluate the gel strength. The anti-temperature, anti-pressure, anti-dilution and gel-breaking properties of the gel were evaluated. Finally, 71 type high temperature and high pressure water loss instrument and high temperature and high pressure filter with slit plate were used to evaluate the plugging capacity of gel plugging agent. The experimental results show that the new gel plugging system between 100°C - 120°C, gelation time can be controlled at about 5 h;it has strong temperature resistance, compression resistance, dilution resistance and gel breaking performance. In the face of permeability and fracture leakage simulation experiments, when the ambient temperature below 120°C, pressure within 5 MPa, the filter loss of gel plugging agent is far less than the market two conventional plugging agent, has excellent plugging performance.
文摘In complex strata, oil-based drilling fluid is the preferred drilling fluid system, but its preparation cost is high, and there are hidden safety risks. Therefore, the new progress of high-performance anti-collapse water-based drilling fluid at home and abroad is analyzed. It is difficult to prevent and control the well collapse. Once the well wall instability problem occurs, it will often bring huge economic losses to the enterprises, and the underground safety accidents will occur. In order to ensure the stability of the well wall and improve the downhole safety, the key treatment agent of water-based collapse drilling fluid is selected, the anti-collapse drilling fluid system is formulated, the evaluation method of drilling fluid prevention performance is established, and a set of water-based drilling fluid system suitable for easy to collapse strata in China is selected to ensure the downhole safety. The development trend of high performance anti-collapse water-based drilling fluid is expected to provide a reference for the research of high performance anti-collapse water-based drilling fluid system and key treatment agent.
