763 results about "Initiation" patented technology

Methods for treating a formation penetrated by a wellbore which improves fluid loss control during treatment. In some aspects, the treatments include preparing an aqueous fluid including one or more water inert polymers and an optional viscosifier, injecting the aqueous fluid into the wellbore at a pressure equal to or greater than the formation's fracture initiation pressure, and thereafter injecting into the wellbore a proppant laden fluid at a pressure equal to or greater than the formation's fracture initiation pressure. The water inert polymer may be a polymer such as an emulsion polymer or a latex polymer. Some methods of the invention use a fluid which may have a normalized leak off coefficient (Cw / sqrt(K)) equal to or less than about 0.0022, 0.0014, or 0.0010. A conventional fluid loss additive may or may not be used in conjunction with the treatment fluid and / or the proppant laden fluid. The water inert polymer may or may not substantially enter formation pores. In another aspect, methods for reducing matrix damage to a formation during a treatment operation include preparing an aqueous treatment fluid formed of at least one water inert polymer, and injecting the fluid at a pressure equal or greater than the formation's fracture initiation pressure.

The invention discloses a preparation method of a star polymer, belonging to the technical field of petroleum extraction. The method adopts a redox initiation system, and carries out water solution radical copolymerization on three water-soluble monomers, including tert-butyl acrylate, 2-acrylamido-2-methylpropane sulfonic acid and acrylamide. The redox initiation system comprises trihydroxymethyl phenol, persulfate, hydrogen peroxide, urea, sodium formaldehyde bisulfite, azoisobutyronitrile, chain transfer agent and surfactant. The molecular weight of the star polymer prepared by the method is 8-15 million; the star polymer is water-soluble; the content of the residual monomers in the product is less than or equal to 0.1 wt%; and the star polymer and a crosslinking system, which is composed of water-soluble phenolic resin and polyethylene imine, can form a movable gel system for carrying out deep profile control on a high-temperature high-salt oil reservoir of which the salinity is 117000 mg / L and the temperature is 140 DEG C.

A process is provided by which a polyrotaxane including cyclic molecules having a relatively long graft chain is easily obtained. Also provided is a polyrotaxane which includes cyclic molecules having a radical polymerization initiation site and is for use as a raw material in the process. The polyrotaxane comprises: a pseudo-polyrotaxane comprising cyclic molecules clathrated with a linear molecule, the cavities of the cyclic molecules having been pierced by the linear molecule; and blocking groups disposed respectively at both ends of the pseudo-polyrotaxane so as not to release the cyclic molecules. The cyclic molecules in the polyrotaxane have a radical polymerization initiation site.

The invention discloses a method for preparing polyether polyol in a recycling manner by the aid of a DMC (double metal cyanide) catalyst. The method includes carrying out polymerization reaction on first low-molecule alcohol and alkylene oxide to obtain polymers with low molecular weights; carrying out reaction on the polymers with the low molecular weights, DMC, acid and alkylene oxide, simultaneously filling the polymers with the low molecular weights with a certain quantity of second low-molecule alcohol used as a raw material to obtain intermediate target polymers; preparing target polymers from a part of the obtained intermediate target polymers and preparing other intermediate target polymers from another part of the obtained intermediate target polymers in a recycling manner. The first low-molecule alcohol is used as a raw material. The polymers with the low molecular weights are used as initiators, the DMC is used as the catalyst, and the acid is used as an auxiliary. The average molecular weight of the intermediate target polymers is identical to the average molecular weight of the polymers with the low molecular weights. The method has the advantages that the polyether polyol can be prepared by the aid of the method in the recycling manner without alkali manufacturing initiators, and accordingly loss of materials and discharge of filter residues and wastewater can be reduced; the DMC catalyst in reaction systems for initial reaction is already activated under the condition that the concentration of the DMC in the target polymers keeps identical, accordingly, the dehydration time and the initiation time can be shortened to a great extent in production procedures, and the utilization efficiency of devices can be improved.

A diene rubber (A) having a weight average molecular weight (Mw) of 100,000 to 3,000,000, an Mw / number average molecular weight (Mn) ratio of 1.30 to 2.50, and an Mw / peak top molecular weight (Mp) ratio 0.70 to 1.30. A rubber composition comprising the diene rubber (A) and a diene rubber (B) having an Mw of 2,000 to 90,0000 and / or an oil extender for rubber has good processability and can give a rubber vulcanizate having high tensile strength and good abrasion resistance. The diene rubber (A) is produced by conducting a living polymerization of diene monomer in a hydrocarbon solvent; adding a polymerization stopper to a polymerization mixture at a conversion of 5 to 98% to deactivate 10 to 90% by mole of active terminals present as of the initiation of polymerization; and finally adding a polymerization stopper to completely terminate the polymerization reaction.

The invention discloses an acid liquor friction reducer and a preparation method thereof. According to the invention, the preparation method comprises the following steps: weighing monomer 2-acrylamide-2-methylpro panesulfonic acid; placing into a beaker; adding deionized water for dissolution; adding caustic soda flakes to adjust to the pH value of the system to be 8-10; adding monomer acrylamide and long-chain cation monomer; mixing under the condition of supplying an inert gas; adjusting the water bath temperature to be the initiation reaction temperature and adding an initiator; reacting to obtain transparent gelatin blocks; manually cutting the transparent gelatin blocks; drying, smashing, and screening with 100 mesh to obtain powdered acid liquor friction reducer. According to the invention, the synthesis method is simple, the raw materials are easy to obtain, and the cost is lowered; the acid liquor friction reducer prepared by the invention has a friction reducing rate as high as 65%, the pump pressure is reduced, the pipe line loss is reduced, and the service life of equipment is prolonged; the acid liquor friction reducer is good in temperature tolerance and compatibility, and has a certain speed reducing effect.

The invention provides a hydrophilic phenylboric acid functional porous integral material, which is a cross-linked framework structured hydrophilic phenylboric acid functional porous integral material with penetrated transparent ducts, is formed by 4-(-3-butenyl sulfone) phenylboric acid and crosslinker N,N-bisacrylamide under initiation of a free radical reaction initiator, and can perform a covalent interaction with dihydroxyl compound under a neutral pH condition. The hydrophilic phenylboric acid functional porous integral material can be used for specifically identifying, separating, enriching or immobilizing the dihydroxyl compounds. The invention also discloses a method for preparing the hydrophilic phenylboric acid functional porous integral material.

The invention discloses a hydrophobic association polymer containing capsaicine and sulfonyl, and a preparation method thereof. During the preparation, compounds containing capsaicine functional groups, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and (methyl) acrylic acid long-chain fatty alcohol ester are polymerized under the initiation of a a redox initiator; the mole percentage ratio of the compounds containing the capsaicine functional groups, the acrylamide, the 2-acrylamide-2-methylpropanesulfonic acid and the (methyl) acrylic acid long-chain fatty alcohol ester is 0.5-5 to 65-92.5 to 6.5-20 to 0.5-10; the reaction temperature is 30 DEG C to 120 DEG C; and the reaction time is 1h to 20h. The preparation method simultaneously introduces sulfonyl that is insensitive to salt and capsaicine functional group units with rigidity into the large molecules of the hydrophobic association polymer, thereby obtaining the water soluble hydrophobic association polymer which has high tackification and the properties of anti-salt and high temperature resistance, and can be applied to the tertiary oil recovery in oil fields as a novel oil-displacing agent.

The invention provides a method for preparing a gradient copolymer. In the method, based on the special chain transfer function and self-emulsification function of an amphiphilic reversible addition fragmentation chain transfer agent (amphiphilic RAFT reagent), under a condition of no emulsifier, the gradient copolymer is made from comonomer units by using a thermolysis initiator for initiation and water as a disperse phase and spontaneously by adopting a once feed method when the reactivity ratio of comonomers is high or forcefully by adopting a reaction material supply method when the polymerization reactivity ratio of the two comonomers is small. The molecular chain of the copolymer prepared by the method has a gradient, namely along a molecular chain, the leading position is gradually transferred from one monomer unit to the other monomer unit. The gradient copolymer is used in fields of gradient functional coatings, polymer bulking agents, damping materials and the like. The method is simple, low in cost and pollution free, and makes the control of a molecular chain structure and a polymerization process easy.