Abstract: A lubricant composition includes (a) a hydrocarbon oil including at least 30%wt of isoparaffins, based on the total weight of the hydrocarbon oil, and (b) an alkoxylated natural oil. A method of using the lubricant composition in a water- based composition, in particular a water-based mud, to improve the lubricity and/or to reduce the foaming properties of the water-based composition is also disclosed.

Abstract: A method for determining a concentration of solid particles in a drilling fluid. The method comprises determining, based on a received dimension of a section of a fracture, a plurality of wirelines each having a diameter. For each wireline, the method determines if a solid particle or a part of a fluid is in the current wireline. If it is determined that a solid particle is in the wireline, then determining whether the current wireline is sealed. These steps are reiterated. The method further comprises determining a volume of injected fluid into the fracture and comparing the determined volume with a reference to determine if a fracturing criterion is met. If the fracturing criterion is met, it is possible to modify the current concentration of solid particles.

Abstract: A method for determining a concentration of solid particles in drilling fluid, wherein the method comprises determining, based on a received dimension, a plurality-of wirelines, each determined wireline having a diameter. In addition, for each current wireline, the method comprises: determining if a solid particle or a part of a fluid is in the current wireline. If it is determined that a solid particle is in the current wireline, determining whether the current wireline is sealed; then reiterating said steps. The method further comprises determining a volume of injected fluid into the fracture and comparing said determined volume with a reference to determine if a fracturing criterion is met. If the fracturing criterion is met, it is possible to modify the current concentration of solid particles.