Study On Downhole Throttling Technology In Natural Gas Wells

There are two main problems during the production of natural gas: there will be hydratesthat may form in the bore hole and channel during the production of natural gas, which maycause the problems of being frozen and blocked; there may be accidental hidden troublesbecause of the excessive transportation pressure of channel.. Thus, this paper develops thestudy on downhole throttling technology in natural gas wells.The basic properties and structures of hydrate, the formation conditions of hydrateduring the production of natural gas have been studied, the influential factors (temperature,pressure, water production, composition, condensate oil) that influence the generation ofhydrate have been determined, the process of nucleus formation has been described, andaccording to the temperature and pressure of bore hole the generation of hydrate could bepredicted, the feasibility of the predictive way could be verified by incorporating the actualproduction of Chang36well. Some methods of the prevention of hydrate have beenintroduced, and according to the conditions of hydrate formation, the study on downholethrottling technology has been developed. The calculation models of throttling parameter (theoutward transportation pressure of well head, the reasonable diameter of downhole throttlingglib, the least setting depth of downhole throttling) have been developed, by incorporating thedesigning path of downhole throttling and optimization the throttling technology parametersof Chang36well have been designed, the downhole throttling production system of ChangShen D1-2well has been adjusted. By incorporating the actual situations in well site, thesuitability of Deng Louku horizontal well, Long Shen1Ping1well, Long Shen101well hasbeen separately analyzed, and under the conditions of different temperatures, pressures andalcohol injection rate the applied situations of downhole throttling technology have beenreceived. The matching technology of downhole throttling has been studied systematically,the theory of throttling and atomization and its features have been developed during theprocess of water drainage and gas production, and according to the simulation of throttlingflow field and the decision of liquid loading feature, the reasonable measure of water drainageand gas production has been established. According to the failure analysis of downholethrottling, the control path of safe production has been established. By using theimplementation situation of break down scheme in Xing2-1-1well, the break downtechnology of downhole throttling has been analyzed. At last, according to the productioncurves before and after the recompletion, the equivalent throttling effect of bore hole has beenanalyzed.