Laboratory modeling of fines migration in oilfields
Arien Centa, Ray Mohtar
Engineering Honours Group Project 2009
University of Adelaide
The migration of fine particles in oilfields occurs due to fluid movement in low consolidated sandstones, heavy oil reservoirs, or due to salinity changes during water-flooding. There has been an increasing trend in Australian and other regions for oil companies to move into deeper offshore waters where fines migration is frequently a challenging problem. The mathematical model for fines migration in porous media was developed early in the twentieth century, however validation of the model is difficult because of the extremely small scale of the particles and forces involved.
This project examines the behavior of particle detachment by deep bed filtration methods and the dependence of particle detachment on several filtration parameters. By considering the balance of various relevant interaction forces a theoretical analysis was carried out to assist in laboratory design. Design objectives included the ability to study the effects of particle size and concentration, and to determine the effect on the differential pressure across the filter bed. During experimentation the filters were first exposed to a particulate solution to demonstrate particle capture and retention, and to simulate formation damage. In further laboratories the filters were exposed to particle free solutions to measure particle detachment and release rates into the producing stream. Both sets of experiments confirmed the dependence of particle detachment on particle size and flow velocity as predicted by the analysis.
A primary goal of this project is to design a laboratory and experimental procedure with the ability to measure the strength of the electromagnetic surface forces that stabilise and retain fines in reservoirs. The project involves the design and implementation of laboratory apparatus and the execution of laboratory studies with the objective of providing recommendations for minimising formation damage under fines migration. This project is a part of the industrial Research and Development project that is currently being performed at The Australian School of Petroleum, in partnership with Santos Limited.