Injected Steam Heat Loss And Production Rate Of SAGD

Heavy oil has abundant reserves. Steam assisted gravity drainage (SAGD) is an efficient way of developing heavy and ultra-heavy oil, but it has problems of technical difficulties and high economy risk. How to make sure of the injected steam's situation at bottom of well is the key for accurately predicting output variety. Based on the investigation of production practice and various petroleum literatures in and out of nation and by using hydrodynamics, heat transfer, numerical method, production engineering and modern completion method, I made a deep research on heat loss of surface pipeline and production string of steam injection heavy oil fields and built a steam heat loss forecast model firstly, then improved on oil and water production rate formula of SAGD based on the heat loss model, and built a dynamic forecast model. These work provide an effective evaluate method for steam assisted gravity drainage.The heat loss model could calculate the surface pipeline's heat loss ether it lays in air or buries underground. Four kinds of production string heat loss can be calculated by the model, namely tubing, tubing and packer, heat insulated string, heat insulated string and packer. The following factors were considered in heat loss calculating model, namely various valves, elbows, compensator, tube diameter, various injection conditions and injecting pipe's eccentric structure. Through checkout in site, the model is in good agreement with the data of site test. By utilizing the heat loss model, sensitive factors to heat loss were researched and made an economy analyses for choosing fit production string in BZ7 oil field.Associated the heat loss calculated results with production mechanism of SAGD, through using heat transfer and conversation of energy methods, it improved the calculation formula of oil and water production rate and built a forecast model in this article. Through comparing the results of analytical calculation with numerical simulation, the results proved the model's availability. Then it used the analytical model for analyzing sensitive factors that influence the effect of SAGD and obtained valuable theoretical conclusion, which could also direct real production.Through the research of this thesis, the mathematical model of injected steam heat loss and SAGD output were proposed, the corresponding sensitive factors to heat loss and SAGD production were analyzed. It's very significant for further study of SAGD technique and efficient development of heavy oil.