Abstract: Viscoelastic compositions suitable for use as diversion agents in a process for acidizing a carbonate-based subterranean oilfield formation are disclosed. The compositions comprise water, a tall oil fatty acid (TOFA)-based amidoamine betaine, a C1-C4 alcohol, and propylene glycol. The invention includes an acidizing process that utilizes a mineral acid and an effective amount of the viscoelastic composition. The viscoelastic compositions effectively divert acid flow, thereby optimizing acid utilization and minimizing acid spend. The compositions fully develop formations, stabilize and/or promote formation of worm-like micelles, and maintain a high, stable viscosity during an acidizing process. Surprisingly, the compositions perform well at low surfactant does, high pressures, and temperatures greater than 350° F. The compositions can tolerate higher levels of corrosion inhibitors than known alternatives and can be used in formations having ferric ion contents greater than 10,000 ppm.

Abstract: The present patent application discloses a low toxicity and high biodegradability drilling fluid composition in the form of an inverse emulsion containing an oil phase and an aqueous phase, wherein said oil phase comprises a mixture of at least two diesters obtained from the esterification of a carboxylic acid and an alcohol. The selected diesters are suitable for use in drilling of crude oil or natural gas deposits, exhibiting good stability in the formulations assessed under conditions of high pressure and high temperature and in the presence of divalent salt brines.

Abstract: The present patent application discloses a low toxicity and high biodegradability drilling fluid composition in the form of an inverse emulsion containing an oil phase and an aqueous phase, wherein said oil phase comprises a mixture of at least two diesters obtained from the esterification of a carboxylic acid and an alcohol. The selected diesters are suitable for use in drilling of crude oil or natural gas deposits, exhibiting good stability in the formulations assessed under conditions of high pressure and high temperature and in the presence of divalent salt brines.

Abstract: The deposition of organic materials originating from crude oil, such as asphaltenes and paraffins, is deemed to compromise satisfactory oil exploration and production, because it clogs pores and equipment, compromising the operation performance. This problem may arise at various points during the operations of drilling, stimulating, fracturing, completing and cementing wells, production, transportation, refining and storage of oil and derivatives, including the use of the fluid in treatments for oil wells and reservoirs, well tubing and annuli, tubing, equipment, and tanks used in treatment processes, transportation and refining of oil and derivatives thereof. The present invention relates to a solvent composition to solubilize such deposits and incrustations.