Overview of Recent Waterless Stimulation Technologies
Authors: Alharith Abdullah , Batarseh Sameeh , San Roman Alerigi Damian , Asiri Wisam 
Published: November 2020

The objective of this study is to provide an overview of recent waterless stimulation focusing on hydraulic fracturing technologies, advantages and disadvantages, limitations, and new technologies under development. Different technologies are presented including proppant-free such as slurry fracturing and in-situ proppant generation, CO2, LPG, Seawater, plasma fracturing, high power lasers, gas stimulation, exothermic reactants, and high energy gas fracturing.

Water-based hydraulic fracturing is commonly used stimulations to recover hydrocarbon specifically from the tight formation. The unconventional reservoir requires pumping and fracturing multistage to maximize stimulated reservoir volume. This technology involves the use of large volumes of high water quality, pumping at high pressure, and filling up the fractures with proppants. Several technologies are presented in an effort to find alternatives to current water-based fracturing technologies. The industry efforts towards waterless fracturing technology are to adapt different technologies into fracturing, for example, the use of plasma to create fractures. The principle of this technology is to store large electric charges and release them in a very short period. Another technology is based on gas combustion to create pressurized gas, which can then create fractures in the reservoir, the use of high-energy laser is used for fracture initiation, and in-situ proppants are targeting chemicals that generate proppant in the fractures. Jetting is also evaluated where acid is injected at a high rate for deeper penetration to create network tunnels. Exothermic fracturing is also discussed which is a technology based on chemical reactions that are triggered at downhole temperatures releasing pressurized gases and creating fractures.

Once the drilling operations of a well are concluded, the well is then completed and stimulated. A typical scenario is to perforate the well using a shaped charge perforating gun followed by acid or hydraulic fracturing to maximize reservoir contact. A considerable reduction in permeability can occur when using conventional shaped charge gun, when the fracturing fluid formulation is not appropriately designed, or when improperly flowing back the fracturing fluids. A thorough investigation of recent non-damaging waterless stimulation technologies is included as an alternative to shaped charge gun perforation or to fracturing with water. If conventional fracturing is to be used regardless, then these technologies can be used to help initiate the fracture by lowering the formation breakdown pressure. In addition, it is possible to use these technologies in producing wells to enhance productivity. The discussion will provide details of each technology: suitable use scenario, methodology of use, limitations, and results of case studies.

As more and more wells require stimulation to be produced commercially, new non-damaging waterless methods are implemented. The importance of this paper is to show these alternative technologies to increase production and minimize damage to reservoirs.