Research On Prediction Methods Of Wax Precipitation During Well Completing Test In Deep Water

Wax precipitation is a serious problem encountered in the oil industry all along, which is accompanied in every connection of oil production. The problem of wax precipitation caused great damage and loss to the oil industry, and it had become a very serious factor to restrict the increase of oil production rate and recovery. Along with the oil and gas extraction development deeply and broadly, it is more and more urgent and necessary to study the wax precipitation problem.This thesis is a study of methods to predict the wax precipitation in the course of well completing test in deep water. Our deep ocean area is containing abundant oil and gas resources. Due to the special environment of low temperature in deep water and the characteristic of high wax content in offshore oil, many problems are encountered in the oil production and test work. So, this study was started in connection with the technical problems encountered.Firstly, the constitute and nature of oil and wax was found out, the wax deposition mechanism and the influence factors and their decepline were studied, the in-house laboratory and mathematical model methods were contrasted and analyzed by literature investigation. The method of thermodynamic model was chosen to study the wax precipitation in this thesis. The model parameters were solved through continuous thermodynamic distillation function, equotion of state and theory of solution. The data of wax appearance temperature at different pressures and wax precipitation amount at different temperatures were calculated by means of the thermodynamic model, which was in good agreement with the laboratory results.An effective method could be set up by comparing the data of analog computation and laboratory results, which was the basis to solve the technical problem of wax precipitation in the deep water well completing test.