Field
Embodiments described generally relate to methods for making emulsifiers that can include one or more tall oils and one or more triamides, emulsified drilling fluids, and methods for using same.
Description of the Related Art
The oil and gas industry has used drilling fluids or “drilling muds” for a number of years to tap subterranean deposits of natural resources. As the total reserves of oil diminish, it has become necessary to drill in areas that were previously inaccessible due to technological or economic difficulties. This has led to the widespread use of oil-based drilling fluids or invert emulsion drilling fluids, which offer greater thermal and chemical stability than water-based fluids, allowing for drilling at extended depths and in other demanding services, such as those involving exposure to high electrolyte concentrations and soluble gases. For example, invert emulsion drilling fluids have been used successfully in drilling hot (e.g., greater than 150° C.) formations as well as those containing hydrogen sulfide. Also, to maximize recovery from each platform in offshore drilling, invert emulsion drilling fluids are favored due to their effectiveness for drilling deviated wells (e.g., angled wells). In particular, the high lubricity of invert emulsion drilling fluids is necessary because of the increased torque exerted on the drill string in deviated drilling.
Invert emulsion drilling fluids are typically formed by blending a hydrocarbon oil with water or brine under high shear conditions and in the presence of a suitable emulsifier. The emulsifier is required not only to form a stable dispersion of water droplets in the oil phase, but also to maintain any solids such as weighting material additives (e.g., barites) or drill cuttings in an oil-wet state. With space at some well sites limited, such as on offshore platforms, and with increasing costs of transport of materials to a well site, there is industry wide interest particularly in drilling fluid compositions that can be formulated and maintained (e.g., stored) with minimal or fewer quantities of solvent and other additives, compared to prior art compositions.
There is a need, therefore, for improved emulsifiers for use in invert emulsions that can be used, for example, in oil well drilling.
USPTO Backgrounds
USPTO Backgrounds