Portland cement clinker LCMs that include Portland cement clinker to mitigate or prevent lost circulation in a well are provided. A Portland cement clinker LCM may include Portland cement clinker, Portland cement, a carrier fluid, and an inorganic consolidation activator. Another Portland cement clinker LCM may include Portland cement clinker and a crosslinked fluid, such as a polyuronide crosslinked via calcium ions or a polysaccharide crosslinked via divinyl sulfone. Yet another Portland cement clinker LCM may include Portland cement clinker and polymer fibers or particulate glass. Methods of lost circulation control using a Portland cement clinker LCM are also provided.

Portland cement clinker LCMs that include Portland cement clinker to mitigate or prevent lost circulation in a well are provided. A Portland cement clinker LCM may include Portland cement clinker, Portland cement, a carrier fluid, and an inorganic consolidation activator. Another Portland cement clinker LCM may include Portland cement clinker and a crosslinked fluid, such as a polyuronide crosslinked via calcium ions or a polysaccharide crosslinked via divinyl sulfone. Yet another Portland cement clinker LCM may include Portland cement clinker and polymer fibers or particulate glass. Methods of lost circulation control using a Portland cement clinker LCM are also provided.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

The present disclosure relates to downhole fluid additives including a clay, a hydroxylated polymer, a cation, and water. The disclosure further relates to downhole fluids, including drilling fluids, spaces, cements, and proppant delivery fluids containing such as downhole fluid additive and methods of using such fluids. The downhole fluid additive may have any of a variety of functions in the downhole fluid and may confer any of a variety of properties upon it, such as salt tolerance or desired viscosities even at high downhole temperatures.

Portland cement clinker LCMs that include Portland cement clinker to mitigate or prevent lost circulation in a well are provided. A Portland cement clinker LCM may include Portland cement clinker, Portland cement, a carrier fluid, and an inorganic consolidation activator. Another Portland cement clinker LCM may include Portland cement clinker and a crosslinked fluid, such as a polyuronide crosslinked via calcium ions or a polysaccharide crosslinked via divinyl sulfone. Yet another Portland cement clinker LCM may include Portland cement clinker and polymer fibers or particulate glass. Methods of lost circulation control using a Portland cement clinker LCM are also provided.

Portland cement clinker LCMs that include Portland cement clinker to mitigate or prevent lost circulation in a well are provided. A Portland cement clinker LCM may include Portland cement clinker, Portland cement, a carrier fluid, and an inorganic consolidation activator. Another Portland cement clinker LCM may include Portland cement clinker and a crosslinked fluid, such as a polyuronide crosslinked via calcium ions or a polysaccharide crosslinked via divinyl sulfone. Yet another Portland cement clinker LCM may include Portland cement clinker and polymer fibers or particulate glass. Methods of lost circulation control using a Portland cement clinker LCM are also provided.

Portland cement clinker LCMs that include Portland cement clinker to mitigate or prevent lost circulation in a well are provided. A Portland cement clinker LCM may include Portland cement clinker, Portland cement, a carrier fluid, and an inorganic consolidation activator. Another Portland cement clinker LCM may include Portland cement clinker and a crosslinked fluid, such as a polyuronide crosslinked via calcium ions or a polysaccharide crosslinked via divinyl sulfone. Yet another Portland cement clinker LCM may include Portland cement clinker and polymer fibers or particulate glass. Methods of lost circulation control using a Portland cement clinker LCM are also provided.

The invention relates to a modified geopolymer and a modified geopolymer composite comprising additive. The additive is preferably an athermanous additive. The modification is with one or more water-soluble compounds, the water-soluble compound is preferably selected from phosphorus compounds, nitrogen compounds, copper compounds, silver compounds, zinc compounds, tin compounds and magnesium compounds. Also, it relates to compositions which contain the modified geopolymer or modified geopolymer composite. The compositions preferably comprise vinyl aromatic polymer and are in the form of a foam.

Trona-accelerated composition for backfilling trenches are described. The compositions consist of aggregate (e.g., sand), Portland cement, Trona, water and sometimes air. The compositions may have a compressive strength of between 10 psi and 100 psi after 4 hours, a compressive strength of between 75 psi and 500 psi after 28 days, and a penetration resistance of between 4.5 tsf and 200 tsf after 4 hours. Also disclosed are methods of filling a trench with fast-setting flowable fill.