Investigation of hot-water flooding after steam injection to improve oil recovery in thin heavy-oil reservoir

Abstract

Cyclic steam stimulation (CSS) is one of the popular methods to recovery heavy oil reserves that play an important role in supplying the energy consumption over the world. To solve the problems during the late CSS, we perform the feasibility study of hot-water flooding (HWF) after CSS with laboratory experiments and numerical simulation. The experimental results revealed the optimized water temperature to conduct HWF is 120 °C and the correct moment to convert is when the oil recovery of steam injection reaches 20%. Based on the geological properties of Jinlou oilfield in China, a series of numerical simulations were run to analyze the influence of several sensitive factors. It is necessary to transform development method because there are large quantities of remaining oil assembling at the inter-well region during the late stage of CSS and this after analyzing the oil saturation, reservoir temperature and oil viscosity distribution. The effect of HWF in reverse-rhythm and compound-rhythm reservoir is satisfactory, but is poor in positive-rhythm reservoir. It is suitable to reservoirs with thickness lower than 5 m and permeability variation coefficient less than 0.3. This study can provide a reference for enhanced oil recovery for thin heavy oil reservoirs after steam injection.

Temperature profiles due to continuous hot water injection into homogeneous fluid-saturated porous media through a line source

“…Physically, this is a way of heating the porous matrix and the fluids therein. The problem is ubiquitous in technological areas like heavy and extra-heavy oil recovery [1][2][3][4][5][6] and for the production and storage of energy in geothermal systems [7][8][9][10][11][12], among others.…”

“…The injection of hot water into a porous medium does imply the simultaneous inflow of mass and thermal energy (enthalpy), both by conduction and advection. In the theoretical treatments, researchers commonly have treated the injection problem as one where the temperature of the injected fluid and the initial temperature of the fluid-saturated porous medium are known, while the spatial and temporal profiles of the temperature of the medium around the injection pipe are computed [1][2][3][4][5][6][7][8][9][10][11].…”

Effects of Packer Locations on Downhole Electric Heater Performance: Experimental Test and Economic Analysis

“…At present, oil shale in situ pyrolysis is the mainstream technology used for oil shale exploitation [5][6][7]. From the perspective of heat transfer, the heat transfer process during heat carrier (superheated steam, nitrogen) injection in steam huff and puff, steam flooding, and oil shale in situ pyrolysis is similar [7][8][9]. Superheated steam or nitrogen is produced on the ground, and then injected into reservoirs via heat insulation pipe [6][7][8][9].…”

“…From the perspective of heat transfer, the heat transfer process during heat carrier (superheated steam, nitrogen) injection in steam huff and puff, steam flooding, and oil shale in situ pyrolysis is similar [7][8][9]. Superheated steam or nitrogen is produced on the ground, and then injected into reservoirs via heat insulation pipe [6][7][8][9]. Therefore, techniques or conclusions found in oil shale in situ pyrolysis can be applied to steam huff and puff, and steam flooding.…”

Impact of Integrated Technologies of Enhanced Oil Recovery on the Changes in the Composition of Heavy Oil

“…Since viscous oil is temperature sensitive, it would be most rational to use thermal processes. The conventional thermal methods for developing oil fields (in their various modifications) are usually clustered into three groups: in-situ combustion, thermal steam treatment of bottom-hole zones of wells, and injection of steam or hot water as heat carriers into the reservoir (nonisothermal displacement) [5,6].…”