Feasibility Research And Analysis Of The Oil Well And Water Injection Well Corrosion Control Technology Of Dingbian Oil Field

The produced liquid properties of Dingbian oil field were analyzed, and it corrosion propertie have been tested in laboratory and oil filed by the weight-loss corrosion method. The results showed that:the water type of Yanchang group is CaCl₂, and the main reason for corrosion is high salinity, especially pitting corrosion caused by Cl-;the water type of Yanan group is Na HCO₃, corrosion reason is mainly caused by bacteria（SRB） and hydrogen sulfide corrosion;With the well depth increases, the corrosion rate increases, the increscent of corrosion rate within the range of 750 1750 m is fastest; the corrosion rate were increased with the increase of CO₂ concentration that influence Yanan group more;Under the same concentration of H₂S, p H decreased, the corrosion rate increased, when the concentration of H₂S under high temperature（80 ℃）reached 200 mg/L, the corrosion rate is the largest,but corrosion rate increased with H₂S concentration increasing under low temperature（28 ℃）;Corrosion rate increased with the increase of flow,and speed up after the 0.5 m/s.Imidazoline quaternary ammonium salt, quinoline quaternary ammonium salt and quinoline bisquaternary ammonium salt were synthesized, three WIKnds of quaternary ammonium salt as main corrosion inhibitor,thiourea, curing agent, dispersing agent, sodium chloride were added to made another three types of solid corrosion inhibitor,and screening the best formula by evaluating the three WIKnds of solid inhibitor properties, such as solubility and corrosion performance.The results showed that the imidazoline quaternary ammonium salt was 25%, thiourea 10%,dispersant 10%,polyethylene glycol 4000 50% and 5% sodium chloride that compose a solid corrosion inhibitor perfectly, which dissolve most stablly can riched 0.16 g/h,when the concentration of 100 mg/L, at the 60 ℃, corrosion rate was 84.1% at CO₂ saturated oil field water.Quinoline quaternary ammonium salt（KLLHB） were synthesized,the dispersing agent, compound additives were screened and the non-corrosibility, antiscale, antiseptic properties of compound inhibitor were evaluated.The results showed that the best inhibitor named KLLHB-Z（15% KLLHB + 10% P9 + 20% 27 +10% WLN+ 15% ZMP + 1% WIK）.when KLLHB-Z concentration was 50 mg/L, at 40 ℃, 168 hours,the corrosion rate is 0.0109 mm/a;When concentration was 200 mg/L, the scale inhibition rate was 83%; and the concentration is 100 mg/L, sterilization rate reached 100% to SRB. When the the concentration was less than 150 mg/L, the KLLHB-Z inhibition effect was better than the Zhongyuan 29#, and the price only 0.48 times.Designed the equipment that can add corrosion inhibitor to oil well continuously and quantificationally,and equipment to water injection system,the inhibition efficiency improved by weight-loss corrosion method when KLLHB-Z used in oil well and water injection system.The results showed that when KLLHB-Z concentration is 200 mg/L, the corrosion rate of steel is controlled under the standard of the 0.076 mm/a,the iron content decreased 44.3%.