The present disclosure to a cementitious plugging wall solidifier for water-based drilling fluid and a preparation method thereof and a water-based drilling fluid.

The present disclosure to a cementitious plugging wall solidifier for water-based drilling fluid and a preparation method thereof and a water-based drilling fluid.

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A method of cementing may include: measuring a feeding rate of water and a feeding rate of cement blend into a cement blender; calculating a cement retarder feeding rate and/or an accelerator feeding rate using a thickening time model, wherein the thickening time model uses at least a thickening time requirement, the feeding rate of water, and the feeding rate of cement blend, to calculate the cement retarder feeding rate and/or the accelerator feeding rate; introducing a cement retarder at the cement retarder feeding rate and/or an accelerator at the accelerator feeding rate into the cement blender; mixing at least the water, cement blend, and at least one of the cement retarder and/or the accelerator in the cement blender to provide a cement slurry; and placing the cement slurry in a wellbore.

A method of cementing may include: measuring a feeding rate of water and a feeding rate of cement blend into a cement blender; calculating a cement retarder feeding rate and/or an accelerator feeding rate using a thickening time model, wherein the thickening time model uses at least a thickening time requirement, the feeding rate of water, and the feeding rate of cement blend, to calculate the cement retarder feeding rate and/or the accelerator feeding rate; introducing a cement retarder at the cement retarder feeding rate and/or an accelerator at the accelerator feeding rate into the cement blender; mixing at least the water, cement blend, and at least one of the cement retarder and/or the accelerator in the cement blender to provide a cement slurry; and placing the cement slurry in a wellbore.

Methods and compositions for treating a subterranean formation with salt-tolerant cement slurries including treating a salt-containing subterranean formation having sodium salts, potassium salts, magnesium salts, calcium salts, or any combination thereof comprising: providing a salt-tolerant cement slurry comprising: a base fluid, a cementitious material, a pozzolanic material, a salt-tolerant fluid loss additive, a salt additive, and optionally, an elastomer, a weight additive, a fluid loss intensifier, a strengthening agent, a dispersant, or any combination thereof; introducing the salt-tolerant cement slurry into the subterranean formation; and allowing the salt-tolerant cement slurry to set.

Methods and compositions for treating a subterranean formation with salt-tolerant cement slurries including treating a salt-containing subterranean formation having sodium salts, potassium salts, magnesium salts, calcium salts, or any combination thereof comprising: providing a salt-tolerant cement slurry comprising: a base fluid, a cementitious material, a pozzolanic material, a salt-tolerant fluid loss additive, a salt additive, and optionally, an elastomer, a weight additive, a fluid loss intensifier, a strengthening agent, a dispersant, or any combination thereof; introducing the salt-tolerant cement slurry into the subterranean formation; and allowing the salt-tolerant cement slurry to set.

Cementing compositions containing a hydraulic cement, halloysite nanoparticles, and silica flour. The cementing compositions may optionally include other additives such as a friction reducer, a defoamer, and a fluid loss additive. Cement samples made therefrom and methods of producing such cement samples are also specified. The addition of halloysite nanoparticles and silica flour provides enhanced mechanical strength (e.g. compressive strength, flexural strength) and improved durability (e.g. resistance to CO.sub.2 and salinity) to the cement, making them suitable cementing material for oil and gas wells.

A geopolymer cementing fluid with controllable thickening time includes the following components in parts by weight: 100 parts of a cementitious material, 10 parts-30 parts of an activator, 0.2 parts-5 parts of a retarder, 0.4 parts-4 parts of an anti-settling agent, and 30 parts-70 parts of water. The geopolymer cementing fluid of the present invention has the advantages of controllable thickening time, excellent compressive strength, good settlement stability, good rheological properties, green and eco-friendly, and the like. The geopolymer cementing fluid can be better suited for the operations of oil and gas well cementing and ensure cementing safety.