556results about How to "Reduce fluid loss" patented technology

An improved fluid loss control additive and methods of using such compositions in surface and subterranean applications are provided. A method of cementing in a subterranean formation, that comprises providing a cement composition that comprises a cement, water, and a fluid loss control additive, the fluid loss control additive comprising an acrylic acid copolymer derivative, an iron compound, and at least one of a hydratable polymer or a dispersant, placing the cement composition into the subterranean formation, and permitting the cement composition to set therein, is provided. Also provided are methods of reducing the fluid loss from a cement composition, cement compositions, and fluid loss control additives.

Of the many methods provided herein, the present invention provides a method comprising: providing a drill-in fluid that comprises an aqueous base fluid, a viscosifier, a relative permeability modifier fluid loss control additive, and a degradable bridging agent comprising a degradable material capable of undergoing an irreversible degradation downhole; placing the drill-in fluid in a subterranean formation; and allowing the relative permeability modifier fluid loss control additive to reduce fluid loss from the drill-in fluid to the subterranean formation. Another example is a method of degrading a filter cake in a subterranean formation comprising: providing a filter cake produced by a drill-in fluid that comprises an aqueous base fluid, a viscosifier, a relative permeability modifier fluid loss control additive, and a degradable bridging agent comprising a degradable material capable of undergoing an irreversible degradation downhole; and allowing the degradable bridging agent to degrade.

The invention relates to a pumping stop sand setting fracture-height-controlling acid fracturing process method applicable to a carbonate reservoir. The method comprises the following work procedures that before the normal fracturing, low-viscosity slickwater is adopted for fracture making, and the initial fracture height is controlled; then, after the slickwater enters the stratum in a way of carrying support agent sand, the pumping stop is adopted for prompting the support agent sand to be settled near a fracture opening, so that each stage of support agent sand shields the back section in advance, a high-intensity artificial separation layer is formed, the stress state is changed, and the goal of effectively controlling the lower fracture height extending to prevent the communication with the lower part water body is achieved; low-viscosity fracturing fluid is injected for fracture making at a stable discharge capacity; after the fracturing fluid enters the stratum, acid liquid is injected for etching the stratum, and high-flow-guide capability artificial fractures are formed; after the acid liquid is extruded into the stratum, the pumping is stopped for measuring the pressure drop, and the construction is completed. The process has the advantages that the artificial separation layer can be formed, the fracture height vertical direction extending can be controlled, the stress state is changed, and the goals of effectively controlling the lower fracture height extending and preventing the communication with the lower part water body are achieved.

The invention provides a leak preventer along with drilling and the method for its preparation, relating to the field of additive of boring fluid. Such leak preventer along with drilling contains: a) plant fiber without colloid or lignin, 100 weight shares; b) lime carbonate with calcium carbonate for at least 90 weight percent, 10-60 weight shares; c) oil-soluble resin of oil-soluble ratio no less than 95 weight percent and softening point 50-250 Deg. C, 3-30 weight shares. The leak preventer along with drilling is prepared by equably mixing the disintegrated ingredients which contains there substances above. It has a remarkable effect of leak prevention, which can be mixed with boring fluid to prevent leak while drilling, needing not stop drilling or stop laboratory sifter, improving the drilling speed and saving the drilling cost. And it also can release stoppage in acid solvent, oil solvent and negative pressure, and protect the reservoir. The leak preventer along with drilling is easy to spread, extensive sources of the material, low cost, and convenient technique.

The invention discloses a production-increasing method by water-plugging and fracture, comprising the following steps: mixing 5 to 7 proportions of crack shielding agents with 100 proportions of clean water; injecting a mixture a into pressed cracks of a well layer under the temperature of 0 to 45 DEG C; shielding an aperture in a storage layer; mixing 5 to 10 proportions of bottom water oil reservoir plugging agent with 100 proportions of low-viscosity fracturing fluid; injecting the mixture generated in step c into cracks pressed in oil layer or gas layer under the temperature of 0 to 45 DEG C; plugging lower water layer after deposition of the mixture; carrying out sand-adding and fracturing operation on the oil layer or the gas layer at the upper part of the storage layer; closing a well and waiting for condensation then fishing the construction. In the method, the bottom water oil reservoir type or the bottom water gas reservoir type gas well bottom is plugged, the jumping-up of bottom water is prevented, simultaneously the crack height is controlled effectively, the extending-down of the crack is prevented, therefore, the aims of plugging the water layer is achieved and the single-well output of an oil well or a gas well is improved.

The invention relates to a drilling fluid, which comprises heterocycle-containing ionic liquid. Compared with the current drilling fluid, the drilling fluid containing the ionic liquid can increase high temperature inhibition performance, and filtration rate is reduced, and system rheological property is not influenced.

The invention offers high density fracturing fluid formula used inorganic salt to improve water-base fracturing fluid density. Its feature is that its weight ratio is as follows: weight additive 4-50%, vegetable gum thickener 0.3-1.0%, cross linking agent 0.1-2.0%, pH value regulator 0.5-1.0%, cracking agent 0.002-0.3%, cleanup additive 0.05-0.5%, fungicide 0.03-0.2%, and water 30-73%. The density of the high density fracturing fluid is adjustable and can exceed 1.51g/cm3. It has good high temperature resistant, shearing resistant, and so on. Thus it can supply reliable assurance for abnormal high pressure and ultra-deep well exploration test oil and exploitation.

The invention provides a tackifier for a drilling fluid, and a preparation method and application thereof. The tackifier is a quadripolymer formed by polymerization of four alkene monomers, wherein the four alkene monomers are selected from a temperature-resistant salt-tolerant monomer, a hydrated monomer and an adsorptive monomer; the temperature-resistant salt-tolerant monomer is selected from an alkenyl sulfonic acid monomer; the hydrated monomer is selected from alkenyl carboxylic acid, alkenyl alkane ketone and double-bond-containing quaternary ammonium salt compounds; and the adsorptive monomer is selected from an alkenyl amide monomer. The tackifier provided by the invention can resist a high temperature of no less than 180 DEG C, is resistant to saturated salt, has remarkable tackifying effect, is low in toxicity and environmentally friendly, and can obviously improve the dehydration and wall building capability of the drilling fluid, thereby effectively reducing the dehydration. The invention solves the downhole complexity possibly caused by the fact that the drilling fluid system can not carry and suspend rock debris and thus can not clear boreholes in time due to reduced viscosity shearing force as a result of poor temperature resistance and salt tolerance of the tackifier in deep well, ultradeep well, horizontal well and extended reach well operations.

The invention relates to a high-temperature-resistant while-drilling plugging agent and a preparation method thereof and belongs to the technical field of oil field chemical drilling fluid treating agents. The method comprises the following steps: preparing a stable emulsion from an oil soluble monomer A, an oil soluble crosslinking agent B, an azo-type initiator, an organic hydroperoxide and water in the presence of an emulsifier, and polymerizing the stable emulsion to obtain a powder M; and swelling the powder M by use of a swelling agent, adding a water soluble monomer C, a water soluble crosslinking agent D and a reductive initiator into the swelled powder M, and polymerizing the mixture at the room temperature to obtain the high-temperature-resistant while-drilling plugging agent. The high-temperature-resistant while-drilling plugging agent is in a powder shape, has relatively high temperature resistance, can resist the temperature up to 180 DEG C, and can be used for performing while-drilling plugging on deep wells and supper deep wells. The while-drilling plugging agent can be used for quickly effectively plugging the permeability leak, the micro order crack and gap leak, avoiding the repeated leak, participating in the formation of a filter cake, keeping the stability of a well wall and obviously reducing the drilling filler loss and the pollution to a reservoir, has no influence on the rheological property of the drilling fluid and has the advantages of good compatibility with various drilling fluid systems and relatively good combination property.

The invention relates to a fracturing fluid system used in an oil and gas field, in particular to a fracturing fluid system of CO2 cleaning foam. The fracturing fluid system comprises the following components in percentage by weight: 0.3-0.8 percent of water-soluble hydrophobic association polymer, 0.25-0.55 percent of rheological auxiliary agent, 0.5-3.0 percent of clay stabilizer, 0.1-0.5 percent of foaming agent, 0.01-0.2 percent of gel breaker, 30.0-80.0 percent of liquid CO2 and the balance of water. Compared with the prior art, in the fracturing fluid system of the CO2 cleaning foam, a cross-linking agent is not needed, the foamability is good, the foam stability is high, the sand-carrying capability is strong, gel breaking is easy to control, no residue is generated after gel breaking, the superficial/interfacial tension of gel-breaking liquid is low, and the damage to the formation is less, and therefore, the fracturing fluid system can be used for fracturing modification of hypoisotonic, low-pressure and water-sensitive storage layers at the temperature of 60-140 DEG C.

The invention relates to a high temperature resistant cleansing emulsion or microemulsion fracturing fluid and a preparation method thereof. The emulsion fracturing fluid is composed of a continuous oil phase, a polymer (I)-containing dispersed water phase and an emulsifier. The preparation method of the emulsion fracturing fluid includes: preparing a mixed solution of the oil phase and the emulsifier, preparing a four-monomer containing water phase, conducting a polymerization reaction in the presence of an initiating agent, and other steps. The product provided in the invention has low apparent viscosity, and can dissolve rapidly. When the emulsion dissolves into gel, the emulsifier can have a synergistic effect with an association polymer, thus further improving and maintaining the viscosity, and helping to prevent leak-off and help flowback. An oxidation gel breaking way is employed for gel breaking, the gel can be completely broken, and the gel breaking solution has low viscosity and contains no residue. The emulsion fracturing fluid is easy to undergo flowback, and has low damage to the stratum.

The invention relates to a filtrate loss reducer for high-temperature-resistant oil field drilling fluid, a preparation method of the filtrate loss reducer, and application of a treatment agent. A novel high-temperature-resistant filtrate loss reducer is synthesized by implementing the following steps: adopting lignin, acrylamide and 2-acrylamide-2-methyl propanesulfonate as synthetic monomers; enabling the synthetic monomers to perform graft copolymerization under the initiation of potassium peroxodisulfate, ammonium ferrous sulfate hexahydrate and hydrogen peroxide respectively; adding a crosslinking agent, namely N,N-methylene bisacrylamide to enhance the stabilizing force of the synthetic monomers under high temperature condition. The filtrate loss reducer disclosed by the invention adopts waste materials of a paper-making factory, is extensive in source and low in cost, and can be used for absorbing the excellent viscosity reduction capacity of lignin; the introduced acrylamide and 2-acrylamide-2-methyl propanesulfonate can be used for improving the precipitation capacity at a high temperature; N,N-methylene bisacrylamide is added as the crosslinking agent to ensure that a network structure is formed, the high temperature resistance can be improved, an oil and gas layer can be protected from collapsing, and the service life of an oil well can be prolonged. A product disclosed by the invention is applied to the oil field drilling fluid.

The invention provides a reversible Pickering emulsion, and the reversible Pickering emulsion comprises an oil phase, an aqueous phase and a nanoparticle activated in situ by an amine surfactant or anamine derivative surfactant. The nanoparticle is a lipophilic, hydrophilic or amphiphilic nano oxide, and the amine surfactant is primary amine, secondary amine, tertiary amine surfactants or derivatives of the surfactants. The lipophilic nanoparticle is activated in situ by a short chain amine surfactant or a short chain amine derivative surfactant; the hydrophilic or amphiphilic nanoparticle isactivated in situ by a long chain amine surfactant or a long chain amine derivative surfactant. The invention further provides a drilling fluid comprising the emulsion. An enhancer for the drilling fluid is an amphiphilic hyperbranched polymer, the density of the prepared reversible high-temperature high-density drilling fluid is directly adjusted within 1.6g/cm<3> to 2.2g/cm<3>, and has the relatively excellent properties of rheological property, suspension stability, filter cake clearance, filter loss control, environmentally friendliness, and reversibility of a water-in-oil emulsion and anoil-in-water emulsion.

The invention relates to a temperature-sensitive-type intelligent nano particles used in a drilling fluid and a preparation method thereof. In the invention, a silane coupling agent is used for performing ultrasound surface modification to nano SiO2 and a vinyl functional group is introduced. With the surface-modified nano SiO2, a temperature-sensitive-type monomer and a hydrophilic monomer are subjected to a polymerization reaction in a water medium with a co-solvent with addition of an initiator, wherein granularity distribution of the temperature-sensitive-type intelligent nano particles is D10 <= 100 nm, D 50 <= 165 nm and D90 <= 260 nm. When the temperature is higher than a sensitive value, the nano particles achieve double functions of both physical blocking and chemical inhibition, so that a continuous compact hydrophobic blocking layer is formed inside shale, thereby achieving effects of preventing and delaying pressure transmission and filtration invasion, and further enhancing stability of a shale well wall.

The invention provides a temperature-resistant and salt-resistant latex blocking agent. The latex blocking agent is prepared from, by weight, 100 parts of hydrophobic monomers, 0.5-25 parts of hydrophilic monomers, 0.1-10 parts of emulgator, 0.01-5.5 parts of a buffer agent, 0.01-4.5 parts of molecular weight modifier, 0.01-6.9 parts of a protective agent, 0.01-2.3 parts of initiator and 67-172 parts of deionized water. The latex blocking agent has good blocking and water loss reduction effects and is resistant to high pressure and high temperature, and a formed mud cake is dense, thin and tough.

The present invention discloses one kind of nanometer composition heat resisting filtration reducing agent and its preparation process. The nanometer composition filtration reducing agent is synthesized through a reverse addition-fracturing chain transferring (RAFT) process, and has nanometer montmorillonite layer dispersed inside amphiphilic block polymer base. The organic combination between rigid and stable montmorillonite and flexible block polymer makes the nanometer composition filtration reducing agent possess high physical and mechanical performance and high heat stability. It is used as drilling fluid treating agent and has obvious filtration reducing effect at high temperature and high pressure.

The invention provides a proppant-carrying acid fracturing method for a high-temperature ultra-deep carbonate reservoir. The proppant-carrying acid fracturing method for the high-temperature ultra-deep carbonate reservoir comprises the following steps that (1) fracture forming is conducted through fracturing fluid; (2) ground crosslinked acid is adopted and is made to react with rock, so that an acid-etched fracture is generated in a formed fracture, and a proppant is carried with the ground crosslinked acid for supporting the acid-etched fracture; and (3) linear glue is used for replacement, and thus acid fracturing is completed. According to the proppant-carrying acid fracturing method for the high-temperature ultra-deep carbonate reservoir, the technique is simple, operation is convenient, and the construction effect is remarkable; and the proppant-carrying acid fracturing method is suitable for transforming construction of deep well carbonatite at the high temperature of 150-170 DEG C, a supporting fracture which has deep penetration and longer flow conductivity can be formed in a stratum, the productivity is increased and the production time is prolonged after acid fracturing and well fracturing, and the length of the formed fracture is larger than 120 m.

The invention provides a drilling fluid and a preparation method thereof. The drilling fluid comprises base slurry and additives, wherein the additives include a high-softening point asphalt composition particle, a performance regulator, a stable dispersant and a stable dispersing aid, the addition amount of the high-softening point asphalt composition particle is 2% to 5% of the total mass of the drilling fluid, and the average particle size of the high-softening asphalt composition particle is 10 to 120 mm. The preparation method comprises the following steps: (1) preparing the high-softening point asphalt composition particle; and (2) adding the high-softening point asphalt composition particle into the drilling fluid and then adding proper additives like the performance regulator, a surfactant and a film-forming additive so as to allow the high-softening point asphalt particle to be uniformly and stably dispersed into the drilling fluid. The drilling fluid provided by the invention overcomes the problem that high-softening point asphalt is hard to be crushed into fine particles and has difficulty in stable dispersion in a water-based drilling fluid, and the drilling fluid can be widely used in the process of drilling operation for deep oil and gas.