Seawater Fracturing Fluid Development Challenges: A Comparison Between Seawater-Based and Freshwater-Based Fracturing Fluids Using Two Types of Guar Gum Polymers

Abstract

During the past several years (i.e., 2006 to 2014), the US transformed the development of shale oil and gas from slow and steady into a shale gas boom by combining two already existing technologies—multistage hydraulic fracturing and horizontal wells. This helped the US once again be energy-independent regarding natural gas supply (Charlez 2015). Inspired by such success, the Kingdom of Saudi Arabia and the Middle East region are meeting the increasing energy demand by following similar steps (Bartko et al. 2012). Large stage sizes in hydraulic fracturing and horizontal drilling long laterals require large quantities of freshwater. Despite the fact that the Arabian Peninsula lacks freshwater resources, fresh water is still consumed by the oil and gas industry in the region. Conversely, seawater is plentiful and should substitute for freshwater in unconventional resource operations. However, the high salinity of seawater raises many chemical challenges in developing design criteria for fracturing fluids. To help mediate this problem, this paper studies the chemistry of developing seawater-based fracturing fluids using two types of polymers as gelling agents and compares results to already existing freshwater-based fracturing fluid data under different conditions. Various seawaters from around the world were compared to Arabian Gulf seawater and its various compositions throughout the year. The local seawater's high total dissolved solids (TDS) measurement is 54 000 mg/L and includes sulfate (>4000 mg/L), calcium (>600 mg/L), and magnesium (>1700 mg/L). These are the major ions that cause delayed hydration, alteration of the crosslinking mechanism, and high scale formation, along with barite (BaSO4). Moreover, the paper presents a better understanding of fluid behavior by studying the effects of sulfate (>4000 mg/L), calcium (>600 mg/L), and magnesium (>1700 mg/L) individually to observe fluid stability at high temperatures in both polymers.

Experimental Investigation and Performance Evaluation of Modified Viscoelastic Surfactant (VES) as a New Thickening Fracturing Fluid

“…[ 13 , 14 ]. At an early stage of hydraulic fracturing, polymer fluids such as guar gum [ 15 , 16 ] was used mostly as a thickening agent for the fracturing fluid [ 17 , 18 ]. Laboratory experiments have shown that traditional polymer-based fluids generate residue(s), which can damage the formation and reduce the pore conductivity.…”

A Critical Review of the Physicochemical Impacts of Water Chemistry on Shale in Hydraulic Fracturing Systems

“…Barium dissolved from the drilling mud remnants can be reprecipitated as Barite . In some cases, large amounts of strontium-bearing mineral precipitates can form due to the nature of the connate brines . This behavior is complex and often basin specific.…”

Chelating Agents Usage in Optimization of Fracturing Fluid Rheology Prepared from Seawater

“…CMHPG guar derivative is preferred in the industry for its better hydration, slower degradation, and tolerance to a low pH environments. Figure 2 shows the generic structure of CMHPG ([ 22 , 23 , 24 , 25 ]).…”