Study On Dynamics Model And Technological Parameters Optimization Of Double-String Production Of Heavy Oil Wells

In view of the technological status on viscosity-decreasing and lift of heavy oil in GuDong oilfield, this paper, deals with the mature technology of it at home and abroad, analyzes the advantages and disadvantages, puts forward a new method, mainly reducing the length of contact between sucker rods and heavy oil, secondarily mixing fluid, and study the feasibility.This paper, explains the principle of double-string technology exhaustively, defines the well configuration and its corollary equipment. By studying the rheological properties of heavy oil, we draw change curve of viscosity with each factors, fit the rheological model through method of least square and ANN, and establish the dynamics model of judging the flow pattern,temperature field,pressure field and rod string checking. On this basis, we draw up the system optimization software by VB, in order to design the system with different rod string and different amplitude and frequency of strokes. According to the field constructed well, we completely evaluate the software by many criteria, which are daily oil production, daily fluid production, daily consumption, and so on. Research has shown: (1) Double-string production can effectively reduce the length of contact of rod string and heavy oil, and decrease the friction of fluid, in order to increase the lift efficiency of heavy oil. (2)Because of different basic data, the rod string and amplitude and frequency of strokes are different by the design of software. (3) Double-string production is restricted not only by the control factor such as the temperature of mixing fluid, the pressure of mixing fluid, oil production, backpressure, but the stratum factor such as water-saturation, reservoir temperature, as so on.The study of rheological properties of heavy oil, system dynamics model and drawing optimization software, is therefore, of practical importance to the application of double-string production at locale. Meanwhile, the analysis and evaluation of effects and feedback from oil wells of practical construction, can also optimize and improve the theory mechanism and optimization software.