Oilfield Chemistry Paper: New, Environmentally-Friendly, Salt-Free Shale Inhibitors

TITLE

Further Development of New, Environmentally Friendly, Salt-Free Shale Inhibitors for Water Based Drilling Fluids

ABSTRACT:

The shale inhibition market is trending towards more environmentally friendly materials. As such, more markets are seeking, or already mandate, lower saline or salt-free systems for reasons including environmental regulations, disposal needs and potential groundwater contamination. This paper will cover efforts to develop and evaluate new shale inhibitors in multiple chemical classes, which satisfy these requirements whilst still maintaining excellent performance relative to industry benchmarks.

Several families of novel candidate chemistries, each comprised of a homologous series, were evaluated using a variety of techniques, namely shale recovery, hardness, linear swell meter, and Slake Durability (roller cage) tests. These tests were followed by biodegradation and toxicity evaluation. This approach identified several inhibitors with improved performance across multiple parameters, both technical and environmental. Beyond discovering new shale inhibitor chemistries, it is important to understand the testing protocols used for their analysis. As part of this research, shale testing protocols, including a linear swelling method, were developed and utilized. This paper will discuss the evaluation process, the measured performance of the molecules synthesized in this study, structure/property relationships, and detailed environmental and performance analysis of the top inhibitor chemistries.