Volume 7, Issue 2 (9-2023)
Abstract
Research topic:
Gas lift is an efficient artificial lift strategy, routinely used to overcome the low productivity of the wells. In this research, the possibility of using two gases, carbon dioxide and nitrogen instead of natural gas, in the gas lifting process is investigated and compared. To maximize oil production, the optimization of the allocation of the limited amount of gas between 10 wells in the Iranian offshore brown oil field is performed.
Research Method:
In this research, all the wells were modeled by PROSPER software. First, all 10 wells data of an Iranian offshore oil reservoir were collected. Secondly, their model has been built and after validation, a simulation of the artificial gas lift was performed using carbon dioxide and nitrogen gas separately, then, the Gas Lift Performance Curve (GLPC) of all the wells are fitted with the appropriate experimental model in MATLAB software. In the following, using Solver Excel, the allocation optimization with a limited amount of gas was performed using two different gases.
Main results:
According to the results obtained from the optimization, for a certain amount of available gas which is 15 MMSCFD, the total Oil production in the case of nitrogen gas injection is 3564 STBD more than carbon dioxide gas injection. Also, in all cases, due to the production potential capacity of well No. 8, the most amount of injected gas is allocated to it. The comparison of the two types of injected gas shows that the quantity of oil produced using nitrogen is 3424 and 3302 STBD (28 % and 24 %) greater than carbon dioxide gas when the gas is lowered to 12 and 9 MMSCFD, respectively.
Saeed Ghobadpouri, Ebrahim Hajidavalloo, Amin Reza Noghrehabadi, Younes Shekari, Mohsen Khezrian,
Volume 16, Issue 6 (8-2016)
Abstract
In this paper, gas-liquid two-phase flow in the annulus of a real well during under-balanced drilling operations is simulated numerically. Oil and gas flow from the reservoir in to the annulus is considered due to under-balanced drilling condition. A numerical code based on one-dimensional form of steady-state single pressure two-fluid model in the Eulerian frame of reference is developed and its results are validated using experimental data from two real wells. The results of numerical simulation show better accuracy in comparison with other researches. Given the importance of prediction and control of the bottom-hole pressure and the amount of oil and gas production during the drilling operations, the effects of controlling parameters such as liquid and gas injection flow rate and choke pressure are discussed. Also, the effects of different controlling parameters on the characteristics of two-phase flow pattern, including liquid and gas void fractions, liquid and gas velocities and pressure distribution along with the annulus are discussed. According to the results, the effects of choke pressure and injected liquid flow rate on the production of the oil from the reservoir are independent of the values of each other and are dependent on the injected gas flow rate.
