Sharif Digital Repository

One of the most important production issues in oil fields is high water production which may lead to wells killing and reduction in an economical production period. With the increment of water production or decrease of reservoir pressure, reservoir drawdown pressure reduces which causes reduction in oil production rate. To preserve the reservoir production, we should apply one of the proposed methods; namely, increasing the reservoir pressure, preventing water source invasion or using artificial lift technique. To compensate this reduction, continuous gas injection into the wells can be used. The injected gas combines with fluid in tubing and the density of the fluid decreases, thereby... 

The coning phenomenon usually occurs in water and gas cap drive reservoirs. Water coning in Iranian hydrocarbon reservoirs is one of the most important problems that affects the cumulative production, operation costs and causes environmental problems. Before producing from a reservoir, its fluids are in equilibrium and their contact surfaces remain unchanged, but after starting production from the reservoir, when the viscous force overcome gravitational force in vertical direction, contact surfaces will displace and coning will occur. So, the production rates will be controlled in a range that prevents entering water and gas to the production well. For this reason, investigation and modeling... 

The coning phenomenon usually occurs in water and gas cap drive reservoirs. Water coning in Iranian hydrocarbon reservoirs is one of the most important problems that affects the cumulative production, operation costs and causes environmental problems. Before producing from a reservoir, its fluids are in equilibrium and their contact surfaces remain unchanged, but after starting production from the reservoir, when the viscous force overcome gravitational force in vertical direction, contact surfaces will displace and coning will occur. So, the production rates will be controlled in a range that prevents entering water and gas to the production well. For this reason, investigation and modeling... 

This study aims at the simultaneous determination of relative permeability and capillary pressure from steady-state corefloods. Besides using the measurements of pressure-drop across the core and average saturation under steady-state conditions, we use the transient data between the sequential steady states. The inverse algorithm is based on four type curves “stabilizsation period versus water-cut” revealed by asymptotic analysis of the transient solution near end-point saturations, and on the exponential shape of transition data histories observed by direct numerical runs. The transition measurements are approximated in the stabilisation periods by the type curves using non-linear... 

For traditional calculations of relative phase permeability (Kr) from coreflood Steady-State Test (SST), the capillary pressure (Pc) is required. Usually, Pc is determined from a separate test, using a centrifuge or porous-plate methods. However, during SSTs, water cut and pressure drop are measured during the transition period between two sequential fractional-flow steps. We developed a novel method for simultaneous determination of Kr and Pc from SST by using both steady-state and transient data. In the proposed method, the transition data on the pressure drop across the core are used instead of the traditionally utilised Pc-curve. The main idea is that the stabilisation period during each... 

The objective of this study was to experimentally investigate the performance of water-alternating gas (WAG) injection in one of Iran's oil reservoirs that encountered a severe pressure drop in recent years. Because one of the most appropriate studies to evaluate the reservoir occurs generally on rock cores taken from the reservoir, core samples drilled out of the reservoir's rock matrix were used for alternating injection of water and gas. In the experiments, the fluid system consisted of reservoir dead oil, live oil, Co 2, and synthetic brine; the porous media were a number of carbonate cores chosen from the oilfield from which the oil samples had been taken. All coreflood experiments were... 

Flow assurance is a major challenge in offshore and deepwater operations. Conventional approaches for preventing gas-hydrate formation involve using thermodynamic inhibitors (e.g., methanol, glycol) or kinetic hydrate inhibitors or operating outside the hydratestability zone by insulating the pipeline and/or active heating. These techniques are not always economical and in some cases are not practical for deepwater operations, long tiebacks, or aging reservoirs with high water cuts. The industry needs new and novel flow-assurance techniques to address these challenging conditions. The approach presented in this paper is a wet cold-flow-based method in which gas-hydrate management rather than...