Emerging Fluid Design with Enhanced Proppant Carrying Capacity: An Integrated Geomechanical Workflow

Abstract

The overall success of a hydraulic fracturing treatment and the resulting fracture properties, such as length, height extent, and conductivity, are dictated by the proppant -transport- distribution and its mechanical behavior -effectiveness- within the stimulated fracture network. With the goal of minimizing (eliminating) proppant settling and optimize required horse power on location reducing equipment foot print and volume of water required; an engineered low-viscosity fluid with high proppant carrying capacity has been implemented to improve proppant transport and zone coverage in stimulated fracture networks. An integrated methodology to optimize the emerging fluid design and proppant placement, is presented.

To evaluate and quantify the efficiency of the proppant transport process with a novel low viscosity fluid, an integrated geomechanics workflow was developed combining quick look analysis (i.e. candidate selection) with advanced computational models (i.e. geomechanical models) to improve proppant deliverability. Experiments were conducted to quantify the shear thinning behavior and proppant carrying capacity of the engineered fracturing fluid under different flowing conditions. By honoring experimental results, multiple analytical and numerical models/modules were developed and utilized within the framework of the workflow to assess the designed efficiency.

The novel fracturing fluid is characterized as low viscosity (comparable to that of linear gel), yet it can suspend and transport conventional proppants similarly to a high-viscosity fluid (e.g. crosslink gel), decoupling the need for viscosity with proppant transport. Our analysis indicates that the fluid design (viscosity & proppant carrying capability) and proppant selection type should be customized and evaluated based on the local GeoMechanical conditions. If engineered accurately, fit-for-purpose, fluid can effectively distribute proppant into the fracture surface area, sustaining closure stresses, reducing embedment, and achieving longer effective fracture length(s) and larger conductive reservoir volume with enhanced production.

The formulated workflow can provide an optimized design or improve existing designs based on the reservoir properties and field limitations by iteratively optimizing relevant controls (such as fluid design, proppant type, pumping schedule) of a fracturing operation. Our engineered fluid (EF) technology together with a proposed workflow, demonstrates that fluid design and proppant placement and operational parameters can be customized to maximize production, without compromising for settling and zone coverage.