摘要:
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.
摘要:
The invention relates to a composition comprising 5-50 wt % of calcium silicate hydrate, 10-60 wt % of at least one water-soluble, acid group-containing polymer comprising polyether groups, and 5-40 wt % of at least one polyalkylene glycol ether. Further disclosed is a process for preparing this composition, and cementitious mixtures comprising the composition. A further aspect of the present invention is the use of the composition of the invention in cementitious mixtures for accelerating the development over time of the dispersing action of the acid group-containing polymer after addition of the mixing water and a subsequently accelerated curing of the mixture.
摘要:
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.
摘要:
The present invention relates to methods for providing modified cement compositions having increased slip resistance and/or a decreased setting time in comparison to cement compositions comprising from 1 to 10 weight percent redispersible polymer powder (RDP) and water soluble cellulose ether in a specific amount from 0.1 to 1.0 weight percent, based on the total dry weight of said composition. Also provided are dry mortars comprising cement, RDP, water soluble cellulose ether and one or more additives selected from gelatin, bentonite and combinations thereof for use in such methods, and cement-free mixtures comprising water soluble cellulose ether and one or more additives selected from gelatin, bentonite and combinations thereof which may be added to cement binder for use a for use in such methods.
摘要:
The invention concerns a process for the preparation of a hardening accelerator composition by reaction of a water-soluble calcium compound with a water-soluble silicate compound, said reaction being carried out in the presence of an aqueous solution which contains a water-soluble comb polymer suitable as a plasticizer for hydraulic binders, wherein the water-soluble comb polymer is present as a copolymer which is produced by free radical polymerization in the presence of a phosphorylated monomer and a (meth)acrylic acid ester based polyether macromonomer.
摘要:
The present invention provides a process for forming cement in a well bore. In this process, a cement composition is formed that comprises a cement and one or more beads mixed with the cement. The cement composition containing the beads is displaced into the well bore, and an inert gas phase is introduced to the cement composition to control a density of the cement composition. The inert gas phase can be introduced by adding a gas generating material to the cement composition and/or a porous material to the cement composition. In an embodiment, the gas generating material is a nitrogen generating material that may be activated by an oxidizing agent. In another embodiment, the gas generating material is a hydrogen generating material, e.g., an aluminum powder. The present invention further provides a cement composition comprising a cement, one or more beads combined with the cement, and an inert gas phase created by, e.g., a gas generating material and/or a porous material.
摘要:
A sprayed-on phosphate cement coating formed from the combination and reaction of a phosphoric acid solution and a base metal solution. The acid solution and base solution may be intermixed prior to spraying, during spraying, or on a substrate. The curing reaction rate of the phosphate cement coating and its final physical properties may be controlled by adding various retardants, accelerants, reducers, wetting agents, superplasticizers, buffers, water reducers, adhesive agents, hardening agents, and/or sequestrants to the precursor solutions. The curing rate and properties of the cement coating may be further controlled by adjusting the temperature of the precursor solutions and/or the target substrate.
摘要:
The present invention provides improved traceable well cement compositions and methods. The compositions are basically comprised of hydraulic cement, sufficient water to form a pumpable slurry and a normally non-radioactive tracer compound which becomes radioactive and emits detectible rays over a relatively short time period when exposed to neutrons. The methods of the invention relate to cementing a zone in a well and subsequently detecting the subterranean location of the cement composition therein. A traceable well cement composition of the invention is formed and introduced into a subterranean zone to be cemented. Neutrons are then emitted from a source in the well so that the tracer compound emits detectible rays, the rays are detected and the location of the cement composition in the well is determined.
摘要:
A process for cementing adjacent a subterranean gas-containing zone, in which process a cement slurry containing a stabilized, dispersed gas is placed adjacent the zone. Sufficient gas is present in the cement slurry or is capable of being generated within the slurry to prevent the connate formation gas under pressure from passing into or around the cement prior to the time the cement has set up.