Development and Use of High-TDS Recycled Produced Water for Crosslinked-Gel-Based Hydraulic Fracturing

Abstract

Large quantities of high-total dissolved solids (TDS) produced water are generated during oil and gas production in Eddy County, New Mexico (more than 164 million bbl in 2011). Most of the high-saline produced water is reinjected into disposal wells at an average cost of USD 0.75 to USD 1.00 per bbl. Caused in part by the persistent drought conditions in New Mexico, beneficial use of produced water is receiving attention in the oil and gas industry. One alternative being considered is the use of produced water for hydraulic fracturing operations. Typically, wells in the Delaware basin require 40,000 to 60,000 bbl of fresh water each for hydraulic fracturing job during well development. As such, reclaiming produced water as the base fluid for fracturing not only helps alleviate the industry's dependence on fresh water but can also lower the overall cost of the well stimulation treatment. Using produced water exceeding TDS values of 270,000 ppm is key to reclamation and reuse programs in the Delaware basin. This paper discusses a project to (1) identify the critical parameters and the corresponding optimal ranges in the laboratory, that will allow use of treated produced water as a base fluid for crosslinked-gel-based hydraulic fracturing, and (2) evaluate the validity of the laboratory findings under actual field conditions. High-TDS produced water from a Brushy Canyon producing well near Carlsbad, New Mexico was used as the base fluid for the bench-scale experiments. Crosslinked gels were formulated with carboxymethyl hydroxypropyl guar gum (CMHPG), a zirconium-based crosslinker, sodium chlorite breakers, and other ingredients. The apparent viscosity of the gels was measured using Chandler Model 5550 high-pressure/high-temperature (HP/HT) viscometers. The bottomhole temperature simulated in the experiments was approximately 140°F. The rheological effects of several parameters, including pH, salinity, and scaling tendencies, were evaluated. Other factors, including organics and suspended solids, are included in the discussion. In addition, a field test performed following the bench-scale experiments to validate the laboratory findings under the actual stimulation conditions is discussed. Results indicate that the fracturing treatment using high-TDS produced water successfully created a fracture network and transported sand into that fracture network.

Forward osmosis desalination of oil and gas wastewater: Impacts of membrane selection and operating conditions on process performance

“…Inorganic precipitates are also of significant concern, specifically precipitation of carbonate and sulfate species in the presence of a variety of dissolved ions (e.g., barium, strontium, and calcium) [1,[13][14][15]. While chemical companies and oil field service providers are continually developing chemical additives that are compatible with high TDS, low quality waters [13,16], the opportunity to generate reuse water of varying qualities is of growing interest. This is especially true for companies interested in both water reuse for hydraulic fracturing and treating and discharging flowback or produced waters to the environment in lieu of deep well injection.…”

On the cost of electrodialysis for the desalination of high salinity feeds

“…Opinions vary as to the level of total dissolved solids (TDS) that can be tolerated [10] and a complete understanding of issues of chemical compatibility remains elusive [2]. There is evidence that, with improved chemical formulations, high salinity produced waters may be reused without desalination, particularly in the formulation of fluids for slickwater processes [11][12][13][14][15][16] (processes with high volume flow rates to avoid premature settling of sand, which serves to maintain fractures propped open) and to some extent for cross-linked gel fracturing processes [17] (lower volume flow rate processes employing low molecular weight guar gum based gels to ensure proppant remains suspended). However, the increase in chemical costs associated with such formulations not evident.…”

Water Management: What We Have Learned and What We Need to Consider for Developing a Shale Play in Argentina

“…The authors LeBas et al (2013), Monreal et al (2014), and Kakadjian et al (2013) reported primarily using CMHPG-Zr or alternative systems. Haghshenas and Nasr-El-Din (2014) documented good results with a guar-borate system; however, there was a need to address some ions (calcium and sodium), bringing them to acceptable levels for proper fluid performance.…”