The present disclosure relates to a double-response self-degradable temporary plugging agent and a preparation method thereof. The double-response self-degradable temporary plugging agent is prepared by compounding a crosslinkable monomer with a temperature-sensitive degradablity and an inorganic material with an acid solubility with a first monomer, a dispersant, an initiator and water, and subjecting the resulting mixture to a polymerization.

Disclosed are particulate compositions comprising particles of a blend of one or more polyvinyl alcohol polymers with one or more aliphatic polyester polymers, wherein such particulate compositions are useful, for example, as plugging agents for treatments applied to a subterranean formation traversed by the borehole of an oil or gas well.

The invention relates to the technical field of oil and gas drilling, and discloses an amphiphilic block polymer ultralow-permeability agent and an intelligent temporary plugging type water-based drilling fluid. The ultralow-permeability agent contains a structural unit provided by styryl hydrophobic monomer, maleic anhydride and acrylamide; the drilling fluid contains two or more of water, sodium bentonite, Pac-Lv, the ultralow-permeability agent, calcium carbonate, one-way plugging agent, white asphalt and barite which are stored in a mixed manner or independently stored. When the amphiphilic block polymer provided by the invention is used as the ultralow-permeability agent of the intelligent temporary plugging type water-based drilling fluid, the self-adaptive characteristic is realized; according to the amphiphilic block polymer, temporary plugging layer gaps formed in pore and throats by plugging materials in drilling fluid can be fully filled under the condition that the sizes and the distribution of the pore and throats of reservoirs are not required to be clear, so that the permeability of temporary plugging layer is greatly reduced, ultralow-permeability is realized, and the amphiphilic block polymer is weak in tackifying effect, has gel-improving effect and can improve the rheological property of the drilling fluid.

Disclosed are a temporary plugging agent and a preparation method thereof, and a method for temporary plugging and fracturing of a high-temperature reservoir. The temporary plugging agent includes the following components in mass fractions: acrylamide 5%, composite crosslinking agent 1%, laponite 1%, ammonium persulfate 0.1% and water 92.9%.

Solid shale inhibitor additives and methods of using such additives to, for example, inhibit shale are provided. In some embodiments, such methods include providing an aqueous treatment fluid that includes an aqueous base fluid and a solid shale inhibitor additive, the solid shale inhibitor additive including carrier particles and a treatment composition that includes a shale inhibitor; and introducing the treatment fluid into a wellbore penetrating at least a portion of a subterranean formation.

The present disclosure relates to material for use in oil and gas well completion activities. More particularly, the present disclosure relates to diversion particles, along with methods for making and using the diversion particles. In an embodiment, a composite diversion material includes a non-degradable component comprising two or more non-degradable particulates, wherein the non-degradable particulates have a long term permeability at 7,500 psi of at least about 20 D. The composite diversion material includes a degradable component surrounding at least a portion of the non-degradable component. In another embodiment, a method of making a composite diversion material includes mixing non-degradable proppant particles with an aqueous solution containing a first degradable material to provide a mixture having a proppant concentration of at least about 20 volume percent. The method includes drying the mixture at a temperature of from about 25° C. to about 200° C. to provide the composite diversion material.

The present invention relates to the use of a sequenced polymer as an agent for monitoring the filtrate and the rheology of a fluid injected under pressure into an oil rock, wherein the fluid comprises solid particles and/or is brought into contact with solid particles within the oil rock after being injected, the polymer comprising: a first block which is adsorbed onto at least some of the particles; and a second block having a composition other than that of the first block and a mean molecular weight of more than 10,000 g/mol, for example more than 100,000 g/mol, and which is soluble in the fluid.

A method for reducing water production from a hydrocarbon bearing subterranean formation includes identifying a high permeability zone in the formation and injecting a dense CO.sub.2 composition from a production well into the high permeability zone. The dense CO.sub.2 composition includes dense CO.sub.2 and a thickener soluble in the dense CO.sub.2. The thickener includes a copolymer that is the polymerized reaction product of monomers that include at least one alkenyl ether or dialkenyl ether monomer, at least one acrylate or methacrylate monomer, at least one structural monomer, and at least one allyl ester monomer. After injecting the dense CO.sub.2 composition into the high permeability zone, the method includes withdrawing hydrocarbons from the hydrocarbon bearing subterranean formation through the production well. The dense CO.sub.2 composition blocks pores in the high permeability zone to reduce or prevent flow of water from the high permeability zone into the production well.

A method for enhanced oil recovery from a hydrocarbon bearing subterranean formation includes withdrawing hydrocarbons from a production well extending into the formation, identifying a high permeability streak in the formation, and injecting a dense CO.sub.2 composition from an injection well into the high permeability streak. The dense CO.sub.2 composition includes dense CO.sub.2 and a thickener soluble in the dense CO.sub.2. The thickener includes copolymer. The method includes, after injecting the dense carbon dioxide composition into the high permeability streak, injecting an aqueous treatment fluid into the formation. The dense CO.sub.2 composition blocks the high permeability streak to divert at least a portion of the aqueous treatment fluid into bypassed regions of the formation during the injecting of the aqueous treatment fluid, and the injecting of the aqueous treatment fluid into the hydrocarbon bearing subterranean formation drives hydrocarbons in the hydrocarbon bearing subterranean formation towards the production well.

A reversible gel composition including nanosilica and polyethylene oxide, the nanosilica and polyethylene oxide present at concentrations operable to allow for the reversible gel composition to be a flowable liquid at pH greater than about 8 and operable to allow for the reversible gel composition to be a substantially solid gel at pH less than about 8.