A sulfate-resistant cement composition may contain calcium magnesium aluminum oxide silicate, brownmillerite, dolomite, periclase, and calcium aluminum oxide. The composition may contain the calcium aluminum oxide in an amount in the range of 0.01 to 2.0 wt. %. The composition may contain the brownmillerite in an amount of the range of 20 to 30 wt. %.

Disclosed herein is a method of servicing a wellbore penetrating a subterranean formation, comprising: placing a cementitious composition of the type disclosed herein into the wellbore. The cementitious composition comprises a cement blend and water, wherein the cement blend comprises Portland cement and pozzolan, wherein the Portland cement is present in an amount of from equal to or greater than about 0.01 wt. % to equal to or less than about 25.0 wt. % based on the total weight of the cement blend.

Disclosed herein is a method of servicing a wellbore penetrating a subterranean formation, comprising: placing a cementitious composition of the type disclosed herein into the wellbore. The cementitious composition comprises a cement blend and water, wherein the cement blend comprises Portland cement and pozzolan, wherein the Portland cement is present in an amount of from equal to or greater than about 0.01 wt. % to equal to or less than about 25.0 wt. % based on the total weight of the cement blend.

A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

A wellbore is plugged using a bismuth alloy. The wellbore is arranged so that a liquid bismuth alloy sets with an excess pressure of the plug relative to the borehole fluid pressure along a desired seal height distance.

Methods of wellbore cementing are provided. A method of analyzing a solid particulate including: measuring a water requirement of the solid particulate; and determining an approximation of specific surface area of the solid particulate from the water requirement.

Methods of wellbore cementing are provided. A method of analyzing a solid particulate including: measuring a water requirement of the solid particulate; and determining an approximation of specific surface area of the solid particulate from the water requirement.

A method of pumping a fluid and reactive solid into a mineral formation includes the fluid reacting with the mineral formation to produce a nucleation product. The method may be used in shale formations to seal fissures and prevent leakage. The fluid used in this method may comprise CO.sub.2 and the nucleation products may be the products of carbonation reactions. A cement formed by reacting CO.sub.2 with a reactive solid under deep geological formation conditions is also disclosed.

A carbonation-resistant cementitious blend containing cement, an expandable agent present, a dispersion agent, a fluid loss additive, a defoamer, and an olive waste. Concrete samples made therefrom and methods of producing such concrete samples are also specified. The addition of olive waste provides enhanced durability (carbonation resistance) and maintains mechanical strength (e.g. compressive strength, tensile strength) after exposure to CO.sub.2 and/or brine. The resulting concretes are suitable cementing material for oil and gas wells as well as wellbores for geologic carbon sequestration.

Provided is a frac plug or the like capable of being inserted into a borehole to seal the borehole with high strength, and then quickly disassembled and removed, thereby efficiently producing petroleum. A frac plug according to the present embodiment has a member made of a magnesium (Mg) alloy. The member has a multi-phase structure including a first phase, which is a matrix phase, and a second phase present in the first phase. In the multi-phase structure, the second phase is distributed in a substantially striped pattern in the first phase in a first cross section perpendicular to a second direction of the frac plug, and distributed in a substantially mesh-like pattern in the first phase in a second cross section perpendicular to a first direction of the frac plug.