Experience in Low Viscosity Guar-Free Fracturing Fluid Under Samotlor Field Conditions

Abstract

The recently developed Samotlor 2020 campaign includes a requirement to shift the Frac design to synthetic gelling agent (gellant) which would increase production, keep the reservoir clean and also reduce both capital and operational costs for each stage Frac stage (no need to heat up the water, an option to use the well water, no requirement to miniFrac performance, etc.). The key difference between guar-based gels and synthetic gels is a lower viscosity rating that results in a significant increase in the fracture length and an improved ability to transport high concentration of proppant due to its thixotropic properties (the ability of a substance to lower its viscosity as a result of a mechanical impact and grow its viscosity when still). When gel is destroyed throughout the fracture after the Frac is completed the synthetic option allows for a cleaner fracture and helps remove all residual matter from the fracture. Another important consideration is that guar shipments from India make Russian oil vulnerable to price, foreign exchange and availability fluctuations. If guar crops experience a bad year or Indian farmers determine that the market should be refocused on cotton or other areas (i.e. not guar), the guar prices in Russian would likely skyrocket. The authors worked as a team to come up with a list of clear recommendations to develop both new and existing wells for Lower Cretaceous collectors of the Vartovsk and Megion suites such as AV1 (1-2) and BV8(0) to increase production and reduce capital costs. We have determined that Frac fluids based on synthetic modified polyacrylamide start to come to the front and hold a leading position in the area of production stimulation as previously happened to other effective methods such as polymer water flooding, drilling and cementing applications.