Effect of viscosity on reservoir deliverability of greenfield, Niger-Delta, Nigeria

Abstract

Reservoir deliverability has been a concern in exploration geosciences as it determines the volume of hydrocarbon that is exploitable from a reservoir. In this research, we recorded the viscosity (η) of fluid from Green field in order for us to have an idea of its deliverability. Different quantity of heat was injected in the form of steam into Green reservoir fluids at every 30 minutes interval and the changes in the viscosity at every considered temperature were estimated to determine the reservoir deliverability. Reservoir fluid from Green field were collected every 30 minutes interval to obtain its terminal velocity (VT ) which is needed to estimate η.  The viscosity and deliverability of the reservoir in percentage were 5.073 Nsm-2 and 40% before the injection of steam. Each of the 30 minutes interval of temperature increase after the injection of steam showed a direct variation of the temperature with VT and an indirect variation with η of the fluids. Each of the reservoir fluids collected for five different times from Green field were divided into five portions. After steam injection, the first, second, third, fourth and the fifth collected fluids, respectively, produced an average VT and η of 2.83 ms-1 and 2.164 Nsm-2 , 3.89 ms-1 and 1.576 Nsm-2 , 4.82 ms-1 and 1.272 Nsm-2 , 5.92 ms-1 and 1.034 Nsm-2 and 7.07 ms-1 and 0.865 Nsm-2 which depicts easy movement of hydrocarbon as temperature increases. The percentage average deliverability of the reservoir after the application of heat at five different 30 minutes interval temperature change becomes 53.44% which showed clearly that for non-volatile hydrocarbon, reservoir deliverability can be improved upon by injecting heat as it reduces viscosity and enhances easy mobility of hydrocarbon up the wells.