Analysis of US Fracturing-Fluids Trends Offers Insight Into Changes Over Time

Abstract

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 163875, ’Analysis of US Hydraulic-Fracturing-Fluid-System Trends,’ by Christopher Robart, SPE, PacWest Consulting Partners, Michael Ruegamer, SPE, Kingsfield Consulting, and Alex Yang, PacWest Consulting Partners, prepared for the 2013 SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, USA, 4-6 February. The paper has not been peer reviewed. An analysis of thousands of fracturing treatments in major plays in the United States provides insights into how fracture designs have changed over time. All available data from FracFocus.org were collected, and each fracture treatment was classified into a set of standard hydraulic-fracturing- treatment types. This analysis of changes identifies changes over time in fracture type on the basis of seven broad categories—conventional, water frac, hybrid, energized, acid frac, gas frac, and matrix acidizing. Introduction FracFocus.org was launched in early 2011 to serve as the US national hydraulic-fracturing chemical registry. The registry is managed by the Groundwater Protection Council and the Interstate Oil and Gas Compact Commission to provide the public with access to reported chemicals used for hydraulic fracturing within their area. When this paper was written, nearly 26,000 wells had been reported on the website. Although the FracFocus website was developed with the intention of disclosing to the public the chemicals injected downhole within a given area, the chemical-disclosure data sheets contain a wealth of technical data about hydraulic-fracturing-fluid systems. Every FracFocus chemical-disclosure data sheet contains basic information about the well that was fractured, including date, latitude/longitude, true vertical depth, and water volume. In addition, the data sheet contains detailed information about every additive injected downhole during the hydraulic fracturing, including trade name, purpose, supplier, ingredients, chemical abstract service number, maximum ingredient concentration in additive, and maximum ingredient concentration in hydraulic-fracturing fluid (Fig. 1). See Table 1 for the system developed to characterize hydraulic-fracturing treatments. Analysis of Aggregate US Fracturing-Fluid-System Trends Aggregate fracture trends in the US had shifted dramatically in the 18 months before this paper was written. Drilling and completion activity shifted quickly from a heavy focus on gas plays to oil and liquids-rich plays. In the first week of 2011, 54% of all active land rigs operating in the US were targeting gas, compared with only 24% in the last week of the third quarter of 2012, a decline of more than 50%. At the US aggregate level, fracture-type trends very closely reflect the shift from gas- to oil-focused drilling and completion activity. In the first quarter of 2011, water fracs represented 46% of all hydraulic-fracturing treatments undertaken in the US. By the third quarter of 2012, water fracs represented only 24% of hydraulic-fracturing treatments, a decrease of nearly 50%. This decrease was roughly proportional to the fall in the gas rig count over the same time period. In contrast, conventional fracs increased from 19 to 34% of all hydraulic-fracturing treatments from the first quarter of 2011 to the third quarter of 2012. In the same time period, hybrid fracs increased from 33 to 40% of all hydraulic-fracturing treatments (Fig. 2).