New Experiments and Models for Conformance Control Microgels

Abstract

Water management in mature waterflooded reservoirs is a top priority to push more oil out and control water production. Excess water production through fractures and high permeability thief zones is a growing concern for sweep efficiency and oil production. Gel treatment has been applied widely to plug thief zones and reduce excess water production to improve macroscopic sweep efficiency. Field studies demonstrated that gel treatments can be applied successfully in mature and fractured reservoirs to reduce unwanted fluid production to lower the operating cost causing premature well abandonment. The primary objectives of this work are to conduct laboratory work to understand the transport and propagation of microgel and develop conformance control reservoir simulator to help in screening oil reservoir targets for effective particle gel applications to improve sweep efficiency and reduce the water production. These microgels can be injected as a suspension in water into an injection well. Many experiments were performed to understand the transport mechanism of microgels through porous media and to identify the control variables. The lab data include oil recovery, water cut, resistance factor, residual resistance factor, oil viscosities, gel concentrations, salinity, gel rheology, and gel strength. The success of gel treatment depends on the magnitude of permeability reduction and flow diversion. We have developed correlations for resistance factor, residual resistance factor, and apparent viscosity as a function of gel strength, gel concentration, rock permeability, salinity, and flow rate. The models are validated against lab measurements and implemented into a reservoir simulator called UTGEL. Gel properties such as rheology and adsorption are also investigated. The mechanistic models and numerical tool developed will help to select future conformance control candidates for a given field and to optimize the gel chemistry and treatment.

In situ organically cross‐linked polymer gel for high‐temperature reservoir conformance control: A review

“…method is also using less amount of material that is economically effective especially within the time of low oil prices. 2,19 Some methods used to block high permeability zones which vary from chemical to mechanical treatments, or combinations of both, have been implemented in the industry. Initial trial to reduce water production involved mechanical isolation, cement squeezing, solid-slurry injection, and oil-water emulsion.…”

Oil Recovery from Outcrop Cores with Polymeric Nano-Spheres

“…There are few studies about oil recovery from cores by polymeric particles (Wang 2010;Goudarzi et al 2014). Goudarzi et al (2014) conducted core flood experiments using micro gels (preformed particle gel, PPG) with a particles size of 100-200 nm.…”

“…Goudarzi et al (2014) conducted core flood experiments using micro gels (preformed particle gel, PPG) with a particles size of 100-200 nm. It was shown that the micro gels can reduce the oil saturation of a Berea sandstone core in the tertiary mode.…”

“…Literature review on the flow of the nano-spheres in porous media showed that the mechanism of oil displacement from heterogeneous as well as homogenous porous media is not well established. One of the proposed mechanisms is that prefabricated polymeric particles might reduce the residual oil saturation S or (Goudarzi et al 2014).To validate this, a series of core flood experiments was carried out in order to study this mechanism in both a heterogeneous Boise outcrop and homogeneous Bentheimer outcrop. Saturation of the cores with highly viscous crude oil was done at 50˚C using the porous plates method.…”

“…Literature review on the flow of the nano-spheres in porous media showed that the mechanism of oil displacement from heterogeneous as well as homogenous porous media is not well established. One of the proposed mechanisms is that prefabricated polymeric particles might reduce the residual oil saturation S or (Goudarzi et al 2014).…”