Abstract:
In a process to design high temperature cement sluries, the temperature stable phases (anorthite, wairakite) are selected; aluminum modifiers and silica oxides are added to the dry cement so that the elemental composition of the blend corresponds to the phases selected; the control of the particle size distribution and the relative amount of those minerals allow their addition at high concentration while leaving the slurry easily mixable and pumpable; and the kinetics of the targeted phases formation is then controlled by adjusting the crystallinity and the particles sizes of the different solids.
Abstract:
A system and method for determining the effect of water-soluble additives on oil recovery from carbonate-based rock formations, silicate-based rock formations, and metallic casings leading from such formations provides real-time concentrations of crude oil in test fluids, as compared to traditional core-flooding tests wherein the total amount of recovered and separated crude oil is measured at a later time. The effects of the additives can be determined under elevated temperature and pressure conditions.
Abstract:
Method for controlling lost circulation in a subterranean well using oil-dispersible lost-circulation materials which comprise fibers that are coated (or sized) with a lipophilic coupling agent, a lipophilic film-forming polymer or both. The fibers are preferably between about 6 mm and about 25 mm long, and between about 10 μm and about 200 μm in diameter. The fibers may be added to carrier fluids comprising oil -base fluids, synthetic-base fluids, invert- emulsion-base fluids and combinations thereof. The preferred fiber concentration in the carrier fluid is between about 0.55 g/L and about 28.5 g/L. The carrier fluid may be a drilling fluid, a spacer fluid or a lost-circulation pill.