Flow Simulation Of Steam Injection With Non - Condensate Gas

With the exploration and development of petroleum, as well as the soaring worldwide demand for oil, the exploitation of heavy oil reservoir becomes more and more important. Because of the high viscosity and poor mobility of heavy oil, conventional methods are difficult to exploit cost-effectively. At present one of the main thermal production methods is steam injection, but the technology has some disadvantages:wellbore heat loss, the gravity of steam overlap, steam viscous fingering and steamchanneling in high permeability layer in heterogeneous oil reservoir zones. The issues cause the decrease drastically of the injected steam drynessand volumetric sweep coefficient. So that this article, based on lots of investigation and analysis of the internal and overseas heavy oil reservoirs steam injection technology, the non-condensable gas added in steam injection technique to improve steam quality. This article mainly completed the following work:(1) Based on the theory of non-condensable gas physical parameters, three kinds of the non-condensable gas (nitrogen, carbon dioxide, natural gas) of specific volume, viscosity, thermal conductivity, specific entropy and enthalpy changing with the temperature and pressure was calculated and compared with the tesl data. The results of the comparison show that the formula of physical property parameterscan better predict the physical parameters ef condensate gas. And the different of non-condensable gas were compared on the specific property.(2) Based on theoretical basises of gas-liquid two phase flow model, wellbore pressure gradient, temperature gradient and the steam quality gradient, the non-condensable gas assisted steam injection binary two-phase flow model was established.(3) The wellbore pressure gradient, temperature gradient model was solved coupling by fourth rank Rounge-kutta and the programs were written.(4) Based on the programs of non-condensable gas assisted steam injection wellbore flow simulation and design principle of orthogonal experiment was proposed. We also select the optimal injection parameters plan including three kinds of the non-condensable gas assisted steam by sensitivity analysis of the injection parameters(5) According to the price, equipment, the source of non-condensable gas and the comprehensive score evaluation method which was commonly used in the field, the three kinds of the non-condensable gas assisted steam injection process of their respective advantages and disadvantages was analyzed.The technology of non-condensable gas assisted steam injection can significantly improve the injecting steam dryness in the bottom. The implementation cost less and the technical difficulty is not high. As domestic emphasis on heavy oil exploitation, adding the non-condensable gas in steam injection may be applied widely. Through the study of this article, a new train of thought for increasing dryness of injection steam in thermal recovery of steam injection was put forward which is of great significance for the efficient development of heavy oil.