Modeling of geochemical reactions with fluid flow simulation for scale precipitation and alkaline/surfactant/polymer flooding processes

Precipitation of minerals is a very prevalent and crucial challenge that occurs once there are two different water phases (types), which consist of different concentration of elements, in a reservoir with changing environmental parameters such as temperature and pressure. Most operated oil and gas fields have been facing the problem of deposition of scales around and inside the wellbore since they have not only water injection but also water production. There is a lack of investigation about scale problem because of the uncomprehensive reservoir simulator considering scale precipitation during water injection and production. In this study, an in-house three-dimensional multi-phase reservoir simulator (UTCHEM) is used to model amount of scale precipitation for several cases. In this work, we neglect the effect of hydrocarbon (eg. CH₄, CO₂, and H₂S) dissolutions during scale deposition. Kinetic reactions are coupled with the fluid flow simulator to consider efficiency of water flooding process affected by scale precipitation around the injection and production wells. Several scale deposition and remediation mechanisms are investigated to tune reaction parameters against experimental data at reservoir condition to study transportation, deposition, and remediation of scales near wells. Simulation results show that ignoring scale precipitation in modeling leads to poor prediction for productivity and injectivity of water flood or another enhanced oil recovery (EOR) processes. Simulation study considering scale precipitation totally changes the performance of water flood and production scenarios. Results reveal that the composition of injected water, pH, and temperature of injected water are important factors that control the scale deposition. Meanwhile, these factors are essential to guide the scale remediation process near the wells. We also used the UTCHEM simulator to investigate the effect of temperature on geochemistry reactions during alkaline surfactant polymer (ASP) injection. Such process efficiency that rely on geochemistry reactions are depend on temperature. We also investigate two different relative permeability models in UTCHEM. A case of alkaline/surfactant polymer core flood is established to test this purpose as well as soap generation because of reaction between alkaline and acid components