Reservoir By Gas Injection Minimum Miscibility Pressure Study

The different flooding mechanism acquires the different flooding efficiency. Theory and practice both come to the conclusion that the miscibility flooding efficiency is higher than immiscible flooding efficiency. Two methods' limit is minimum miscibility pressure, that is the minimum pressure which form the miscibility. As a result, it is key to ascertain the MMP accurately so as to realize the miscibility flooding.The following technique routes were adopted: (l)Firstly , I analysis the all kinds of influencing factors , different factors lead to different results; (2)In the experiments, I introduce the slim tube experiment and rising bubble apparatus in detail , including their principal,operation process and methods , then simple recommend the steam density and vanishing interfacial tensions. (3)In theory, Firstly I present classical experience formula and multi-contact miscibility, then simply introduce the EOS(equation of state), including it's main principal and calculation method , and advance a new method aiming at the calculation of MMP, moreover carefully explain this new method's principal and application; (4)Using anexample to compare all kinds of theoretical methods and getting the every method's advantage and disadvantage and application.Through systematical studying, the following results were achieved in this paper: Firstly, It is the first time that negative flash were put forward and were used to set up the analytical algorithms at home; Secondly, a new method, that is analytical algorithms, is brought forward to calculate MMPs for general multi-component systems. Comparing to the other methods, it is more reliable and reasonable and time consuming is less. Thirdly, the effects of different slim tube parameters on MMP were simulated, and reasonable slim tube parameters are put forward on the basis of the reservoir facts. Fourthly, all kinds of methods to calculate the MMP are summarized, and some methods are chosen by the concrete aim. Finally, the MMP on the basis of multi-contact miscibility is bigger than the real result and the errors according to the EOS and experienced formula is big generally.