Synthesis And Application Of Styrene-butadiene Latex (SBL) For Well Cementation In Oil-gas Field And The Technique For Synthesis Of The Powder Acrylonitrile-butadiene Rubber With Medium Content Of Combined Acrylonitrile And Low ML (MLPNBR)

PartⅠSynthesis and applications of styrene-butadiene latex(SBL)for well cementation in oil fieldChapter 1 Advances of studying on SBL for oil-gas fieldThe history of polymers as fluid loss control agents and the mechanism of controlling fluid loss were reviewed. The achievements of SBL as fluid loss control agent were emphatically introduced. In 1990s, GOPACKRISHNAN SKIOHAR Corporation developed a SBL product with thickening temperature up to 180℃. But this agent must be used together with other stabilizing agent. Halliburton Corporation also developed a SBL with thickening temperature up to 176℃. To develop of cheap emulsion or soluble polymer that possess lots of advantageous performances, such as fluid loss control, anticorrosion and the resistance of gas permeation, is a hot topic of cement additives.Chapter 2 Synthesis and application of SBL on stabilizing oil-gas wellThe character of cement mortar and process of stabilizing well have been analyzed. The latex should have the superior performance of chemical and shear stability. According to the mechanism of controlling fluid loss and the resistance of gas permeation,we have designed the sort of emulsify agent and functional monomer. The effects of some factors, such as the kinds and ratio of emulsify agent, monomer, initiator, chain-transfer agent, electrolyte, chain terminator, polymerized temperature and stirring speed of polymerization, on polymerizing reaction and the performance of latex are studied in detail. Through application test, we determinate the optimized process: non-ion emulsify agent as the major one, negative ion emulsify agent as auxiliary agent, acrylonitrile as functional monomer with two patches addition, persulfate as initiator with polymerizing temperature of 40-50℃. The ratios of other components of latex system have also been determined. For the application of SBL we prepared, the cement-water ratio, the latex ratio and the sort, the ratio of other additives of cement mortar, the performance of latex cement mortar, are also studied. We construct the latex-cement mortar system in high density and in low density through measuring the index of thickening rate and temperature, fluid loss, the resistance of preventing gas permeation and the compressive strength of latex-cement rock. This SBL can compound with cement and have superior performances of fluid loss control, resistance of gas permeation and anticorrosion on stabilizing oil-gas well.Chapter 3 The industrial scale-up and performance evaluation of this SBLThe effects of three main factors, such as ratio of initiator, chain-transfer, and polymerized temperature, on polymerization process and SBL performance are investigated at 21M3 polymerizing reactor. The preparative technique of this SBL on industrial scale is determined. The application tests of the SBL indicate that the thickening rate can be adjusted within 3-5 hrs, the thickening temperature can reach 170℃, the fluid loss is less than 50ml, the compressive strength of latex-cement rock is more than 21MPa. This SBL have been succeeded well cementation at LiaoHe and ShengLi oil field. Now more than 50 oil wells have been cemented using this SBL at DaGang oil field.PartⅡStudy on the preparation of powder acrylonitrile-butadiene rubber with medium content of combined acrylonitrile and low ML (MLPNBR)Chapter 4 Advances of studying on the powder acrylonitrle–butadiene rubberThe major methods for the preparation of PNBR, the flocculate-drying method and some factors affecting the ratio of powder in particular, were introduced. The flocculate agent must be added into NBL to produce powder of NBR, and then dry the wet powder with flash dryer. This method has several advantages, such as low energy consumption, dust pollute and high efficiency of drying. In NBL synthesizing, negative ion emulsifier and oxidation-reduction initiator are commonly used, the polymerized temperature is within 5-8℃, polymerized period is 16-20hr with monomer polymerize less than 85%.Chapter 5 Studying on the preparation technique of powder acrylonitrile- butadiene rubber with medium content of combined acrylonitrile and low ML (MLPNBR)The initiator system of persulfate and activator, the sort and ratio of monomer initiator emulsify agent chain-transfer agent, ratio of monomer, chain-transfer agent, electrolyte and chain terminator, and polymerized temperature, the content of combined acrylonitrile of NBL are studied in detail. The ratio of component of synthesis NBL and technological process are determined. Due to the use of persulfate in initiator system, polymerization temperature is within 25-30℃, polymerized period is shorted within 12-14hr, monmer polymerize is more than 98%. ML of NBL can be effectively controlled by the addition of chain-transfer agent in two patches.In NBL flocculation and wet powder drying process, we have studied the affects of some factors such as the sort and ratio of flocculating agent, isolated agent, anti-oxidant and flocculation temperature, stirring speed of flocculating reaction, adding speed of the wet powder, drying temperature,on the ratio of powder. The sort and ratio of auxiliary material and technological process are also checked and determined at 300L flocculating reactor.Chapter 6 The industrial process and performance tests of MLPNBRThe NBL preparation technique is determined after the study of the effects of initiator system and chain-transfer agent on NBL performance at 45M3 polymerizing reactor.At 12M3 flocculantor and spiral flash evaporation dryer of drying 2000 t/a equipments, the main factors such as flocculation temperature and time, the speed of wet power entering dryer, the temperature of drying gas, which affect the ratio of powder, have been optimized. Because of using horizontal centrifugal machine and spiral flash evaporation dryer, the ratio of the powder is more than 95% and dust pollute has been lowed. The performances of the prepared MLPNBR can satisfy with the application demands.