Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

Geopolymeric compositions are presented that are useful as geopolymer slurries for cementing subterranean wells. The slurries may contain an aluminosilicate source, an alkaline source and a carrier fluid. The slurries generate an alkali metal or alkaline earth hydroxide activator in situ, thereby avoiding or reducing handling of alkali materials at a wellsite.

The present development corresponds to a concrete composition for 3D printing comprising cementitious agent, polydisperse matrix, fine materials, plasticizer, concrete accelerator, rheology controller, concrete retarder and optionally concrete shrinkage controllers and/or supplementary cementitious materials (SCMs), wherein the cementitious agent has an addition between 0% and 10% and wherein the mixture between the cementitious, polydisperse matrix, fine materials, and SCMs has a Rosin-Rammler distribution parameter less than 1. The present development is also related to the use of the concrete composition for 3D printing of structural walls and other architectural elements with a mechanical strength greater than 30 MPa and a very high quality of the finished surface.

An efficient sound-absorbing lightweight aggregate cellular concrete, a method for preparing the same, and an application thereof. The concrete comprises: 85-95 parts by weight of low-carbon sulfur-aluminum-ferric cementitious materials, 5-15 parts by weight of supplementary cementitious material, 0.6-1.5 parts by weight of functional admixture, 20-60 parts by weight of non-sintered lightweight aggregate, 0.35-0.45 parts by weight of water, and 0.5-1.5 L of preformed foam. The non-sintered lightweight aggregate includes cementitious materials, byproduct gypsum, hydrogen peroxide, water, and expanded perlite. A multi-level pore structure is constructed from expanded perlite pores, hydrogen peroxide foaming pores, and physical foaming pores. The material exhibits a noise reduction coefficient 0.80, a bulk density500 kg/m.sup.3, and a flexural strength 1.5 MPa.

A method for rapid biocementation of a material under low moisture conditions includes mixing a cell lysate of a urease-producing microbe with the material and, optionally, a calcium source and/or a carbon source, under initial moisture conditions of less than about 15% by weight to form a cementing composition; incubating the cementing composition for a selected time under pressure conditions of between 0 to 1500 bars to form an incubated mixture; and curing the incubated mixture for hours to weeks.

Geopolymeric compositions are presented that are useful as geopolymer slurries for cementing subterranean wells. The slurries may contain an aluminosilicate source, an alkaline source, and a carrier fluid. The slurries generate an alkali metal or alkaline earth hydroxide activator in situ, thereby avoiding or reducing handling of alkali materials at a wellsite.

An air-dry clay moldable and workable for sculptural applications, comprising a formulation of: (1) caulk or caulk base material and (2) a thickening agent and/or a detackifier in sufficient proportions to form a clay that can air dry to a substantially solid form at room temperature. The clay may include both a thickening agent and detackifier. The caulk or caulk base material comprises by weight percent: 40-90%, or 50-80%, or 60-75% of the formulated clay.