Thermochemical Fluid Used in Field Application of Sandstone Stimulation

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 207702, “Novel Sandstone Stimulation Using Thermochemical Fluid: Successful Field Application,” by Amjed Mohammed Hassan, SPE, King Fahd University of Petroleum and Minerals; Ayman Raja Al-Nakhli, SPE, Saudi Aramco; and Mohamed Ahmed Mahmoud, SPE, King Fahd University of Petroleum and Minerals. The paper has not been peer reviewed. Sandstone acidizing is implemented to remove damage from the near-wellbore region. Different techniques are used to remove the formation damage and improve reservoir productivity. This paper presents a novel sandstone stimulation technique using thermochemical fluids. The used chemicals are not reactive at surface conditions and react only at the downhole conditions. The reservoir temperature or pH controller can be used to activate the chemical reaction. A successful field application of the proposed method is reported in the complete paper. Background The literature indicates that strong acids [such as hydrofluoric acid (HF)] can create concerns not only from the reservoir-formation but also from the environmental point of view. HF can lead to severe corrosion downhole and for the surface facility. However, developing a new technique of generating acids inside the reservoir can minimize the negative effects of acid injection significantly. Several approaches can be used for generating acids within the formation of interest, such as capsulation or in-situ acid generation. Different chemicals can be injected to react at downhole conditions to produce acids such as HF. The reservoir temperature or triggering agent can be used to activate the chemical reaction. In this study, the acid foam will be generated in situ in the reservoir formation for the purpose of sandstone stimulation using thermochemical fluids. Different techniques were used to assess the efficiency of the proposed technique. A compatibility study, coreflooding, permeability measurements, scanning electron microscopy (SEM) analysis, and nuclear magnetic resonance (NMR) were performed. Also, the treatment was applied in the field successfully. The in-situ generation of the foam acid can improve well injectivity, eliminate risks associated with environmental concerns, and mitigate corrosion issues.