Engineering Commons^™

Selective Penetration Behavior Of Microgels In Superpermeable Channels And Reservoir Matrices, Yang Zhao, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Gel treatment is an effective way to attack excessive water production in many mature oilfields around the world. Selective penetration is desired for successful gel treatments. That is, gel materials should easily penetrate the target zones (i.e., channeling features such as superpermeable channels) without entering/damaging the nontarget zones (i.e., reservoir matrices or oil zones). This study revealed that presence of threshold penetration pressure (ΔPth) was responsible for selective penetration behavior of tested microgels. The concept of ΔPth was utilized to figure out favorable working conditions for effective gel treatments. Microgel dispersions were injected into superpermeable (super-k) sandpacks (mimicking super-k channels …

Evaluation Of Novel Preformed Particle Gels For Conformance Control And Acid Stimulation Through Core Flooding Tests, Shuda Zhao

Doctoral Dissertations

"Acid stimulation and conformance control are two major methods to improve oil production. This study systematically evaluates two newly developed gels: Degradable Preformed Particle Gel (DPPG) and Re-crosslinkable Preformed Polymer Gel (RPPG). DPPG is designed to be a temporary plugging agent for acid stimulation and can self-degrade into a water-like fluid. RPPG is designed for reservoir sweep efficiency improvement and can re-crosslink to each other and form an immobile bulk gel after being placed in fractures or fracture-like conduits.

For DPPG, this study evaluates the effect of monomer, crosslinker, and initiator concentration on the swelling and degradation performance. Results show …

Enhanced Heavy Oil Recovery By Low Salinity Polymer Flood Combined With Microgel Treatment, Yang Zhao

Doctoral Dissertations

“Heavy oil resources account for a large portion of the total oil reserves around the world. The target heavy oil reservoir is located on Alaska’s North Slope (ANS). Advantages of low-salinity HPAM polymer (LSP) over high-salinity polymer (HSP) were demonstrated. LSP could recover more oil with 40% less polymer consumption. No additional oil was recovered by HSP after LSP flood. The first-ever polymer flood pilot on ANS showed remarkable success regarding water cut reduction, oil production increase, delayed breakthrough, and projected oil recovery improvement. Polymer alone was insufficient to achieve satisfactory recovery as the reservoirs were highly heterogeneous. Microgels could …

Plugging Performance Of Preformed Particle Gels In Fractures And Its Influencing Factors, Ze Wang

Doctoral Dissertations

"Preformed particle gels (PPG) has been successfully applied to combat the water channeling caused by fractures or fracture-like channels. Understanding the placement and plugging of PPG in fractures is crucial for gel treatment design. The objective of the dissertation is to explore the plugging performance of three PPG products in two types of fracture models, the partially and fully open fractures. The following studies has been conducted and conclusions have been drawn based on the results and analysis. First, the placement and plugging performance of conventional PPG was investigated using core flooding experiments conducted partially open fractures. The plugging efficiency …

An Investigation Of Plugging And Increasing Oil Recovery In Sandstone Porous Media By Micrometer-Size Particle Gel, Haifeng Ding

Masters Theses

"Micrometer-size particle gel (microgel) has been developed and successfully applied to improve conformance in mature reservoirs. However, quite few researches have been published to address on their effect on oil recovery and rock permeability modification.

This work conducted a series of core flooding experiments to investigate the injectivity, plugging efficiency and improving oil recovery potentials of a couple of microgels synthesized in our lab.

First, this work studied the impact of permeability and crosslinker concentration on PAM type microgel treatment. Results shows that microgel treatment would have a less plugging efficiency in lower permeability rocks, which could be caused by …

Particle Gel Propagation And Blocking Behavior Through High Permeability Streaks And Fractures, Abdulmohsin Imqam

Doctoral Dissertations

Water channeling, one of the primary reservoir conformance problems, is caused by reservoir heterogeneities that lead to the development of high-permeability streaks and fractures. These streaks and fractures prevent large amounts of oil from being recovered. The ultimate objective of this research was to provide comprehensive insight into designing better particle gel treatments intended for use in large openings, including open fractures, high permeability streaks, and conduits to increase oil recovery and reduce water production.

An intensive laboratory study was conducted to better understand the injection and placement mechanisms of millimeter and micron size preformed particle gels (PPGs) through thief …