3D numerical simulation of clastic reservoir with bottom water drive using various ior techniques for maximizing recovery

Abstract

In most reservoirs with oil rims, as the production begins, the gas-oil and oil-water fluid interfaces start deforming because of the imbalance between viscous and gravitational forces, leading to coning or cusping. This can be overcome using proper withdrawal rate, offset from water-oil contact and horizontal length. Further smart horizontal wells require optimization of nozzle size and compartment length also. To see the effect of these parameters on recovery, a three-dimensional geological model of a clastic reservoir from Upper Assam Basin has been used. This model was history matched for a period of 16 years on 46 wells. After successful validation of model on field scale and well level, performance prediction was carried out to see the effect of withdrawal rate, offset from water-oil contact, horizontal length, compartment length and nozzle size using vertical/horizontal and ICD completion. From the analysis, it is evident that application of advanced well completion, ICD, is suitable for such reservoir. Depending on the scenario, maximum cumulative oil production was obtained from ICD wells with 1.08 MMm 3 compared to vertical well with cum oil production of 0.63 MMm 3 . Economic analysis has been carried out for the examined scenarios.

Laboratory Evaluation on the Water Flooding Characteristics in Bottom Water Reservoir Containing Interbeds

“…19−21 The distribution of interbeds' feature can curb the occurrence of coning water effectively, which has a great influence on bottom water drive reservoir. 22,23 Therefore, it is of great scientific and engineering significance to systematically study the water flooding characteristics in the bottom water−oil reservoir containing interbeds. Wu et al 4 investigated the mechanism of improved oil recovery by nitrogen foam flooding in bottom water reservoirs and revealed that the seepage resistance of foam in the water layer is much greater than that in the oil layer, effectively increasing the displacement strength of the oil layer.…”

“…An interbed is defined as a low permeability sublayer or an impervious stringer in a reservoir bed, such as sedimentogenic muddy intercalation, boulder clay, or diagenetic calcareous layer. In a bottom water drive reservoir, the low-permeability interbeds can prevent the injection water from flooding below the interbed where remaining oil can accumulate or decrease the flooding efficiency of the oil sheet above the interbeds due to their isolation effect. − The distribution of interbeds’ feature can curb the occurrence of coning water effectively, which has a great influence on bottom water drive reservoir. , Therefore, it is of great scientific and engineering significance to systematically study the water flooding characteristics in the bottom water–oil reservoir containing interbeds. Wu et al investigated the mechanism of improved oil recovery by nitrogen foam flooding in bottom water reservoirs and revealed that the seepage resistance of foam in the water layer is much greater than that in the oil layer, effectively increasing the displacement strength of the oil layer.…”

Physical simulation of residual oil displacement production in offshore strong bottom water reservoir

“…It can also increase the viscosity of displacement fluid and reduce the fingering and coning of displacement fluid. Oil in water emulsion is a selective plugging agent (Jacquelin and Erik 2020;Sharma et al 2019). Oil in water emulsion is injected into the oil layer, which more enters the high permeability zone, inhibits the flow capacity of the fluid in the high permeability zone, and thus inhibits the bottom water coning.…”