Development of a Universal Ranking for Friction Reducer Performance

Abstract

In hydraulic fracturing, large amounts of water are pumped at high speed down the wellbore. To reduce pump pressure and costs, a friction reducer is added to the stream. There is currently no unified performance criteria for selection of friction reducers. This work outlines the methodology for producing such a unified method of comparing performance between any friction reducer chemical additives, both liquid and dry powder. A 0.5 inch stainless steel high-flow low-shear flow loop pumping at ranges between three and twenty gallons per minute was custom-built. The loop uses a Coriolis flow meter, two absolute pressure transducers, and one differential pressure transducer to accurately determine the friction reducer additive performance in any given fluid by measuring pressure drop across a section of developed flow. This paper utilizes over 400 in-house flow loop tests to establish a novel unified ranking system for the evaluation of friction reducers’ performance. The ranking is independent of the type of friction reducer used and quality of water. Produced waters, fresh water, treated produced waters, and synthetic waters were all used to validate the methodology and ranking system to create a unified criteria to compare performance of any friction reducers. Tomson Technologies created a standardized metric for assessing and ranking friction reducer performance. This standardization was achieved through the use of an unique performance scale comprised of the weighted average of the most important friction reduction parameters of a friction reducer in any produced water: (1) inversion time (InvT), (2) maximum percent friction reduction (Max% FR), (3) time to sustain maximum percent friction reduction (RetT@%Avg.FRmax), and (4) the percent friction reduction at the end of 500 seconds (% FR@500s). 500 seconds is used because fluid during hydraulic fractures travels from the pumps to the reservoir in 500 or fewer seconds in almost all cases. This scale is measured in a new unit called "Friction Reducer Units" (FRU), which ranges from 0 to 10. FRU has been used to rank and correlate the performance of different classes of friction reducers in various types of waters, resulting in a comprehensive results database and is used to show applicability of the overall metric.