Proppant compositions and methods for using same are disclosed herein. In particular, a proppant composition for use in hydraulic fracturing is disclosed herein. The proppant composition can contain a plurality of particulates and at least one particulate of the plurality of particulates containing a chemical treatment agent. The at least one particulate having a long term permeability measured in accordance with ISO 13503-5 at 7,500 psi of at least about 10 D. The at least one chemical treatment agent can separate from the at least one particulate when located inside a fracture of a subterranean formation after a period of time.

Wellbore fluids may contain an aqueous base fluid comprising a monovalent brine, a modified starch, and a metal oxide. Methods of using wellbore fluids may include drilling a subterranean well while circulating a wellbore fluid into the subterranean well, wherein the wellbore fluid contains an aqueous base fluid comprising a monovalent brine, a modified starch, and a metal oxide.

System and methods for customizing fracturing fluids downhole for real-time optimization of micro-fracturing operations are provided. Downhole operating conditions are monitored during a micro-fracturing operation along a portion of a wellbore within a subterranean formation, based on downhole measurements collected by sensors of a downhole formation tester. Injection parameters for a fracturing fluid to be injected from a bulk storage chamber of the downhole formation tester into the subterranean formation are determined based on the downhole operating conditions. Signals for customizing the fracturing fluid using one or more fluid additives stored within corresponding fluid storage chambers of the downhole formation tester are transmitted to a controller of the downhole formation tester, based on the injection parameters. Injection of the customized fracturing fluid from the downhole formation tester into an area of the subterranean formation surrounding the portion of the wellbore is controlled during the micro-fracturing operation.

System and methods for customizing fracturing fluids downhole for real-time optimization of micro-fracturing operations are provided. Downhole operating conditions are monitored during a micro-fracturing operation along a portion of a wellbore within a subterranean formation, based on downhole measurements collected by sensors of a downhole formation tester. Injection parameters for a fracturing fluid to be injected from a bulk storage chamber of the downhole formation tester into the subterranean formation are determined based on the downhole operating conditions. Signals for customizing the fracturing fluid using one or more fluid additives stored within corresponding fluid storage chambers of the downhole formation tester are transmitted to a controller of the downhole formation tester, based on the injection parameters. Injection of the customized fracturing fluid from the downhole formation tester into an area of the subterranean formation surrounding the portion of the wellbore is controlled during the micro-fracturing operation.

Provided is an enzyme immobilized on an enzyme. Also provided is a viscosified fracture fluid 1 formed by combining a solid proppant, a binding agent and an enzyme to form a proppant-immobilized enzyme 2, mixing the proppant-immobilized enzyme 2 with a second proppant 3 to form a heterogeneous proppant pack 4 and mixing said heterogeneous proppant pack 4 with a gelled liquid fracturing fluid 5 to form a viscosified fracture fluid 1 containing the heterogeneous proppant pack 4. The viscosified fracture fluid 1 containing the heterogeneous proppant pack 4 is pumped 6 into a subterranean zone 7 to form one or more fractures 8 therein. The proppant-immobilized enzyme 2 that is part of the heterogeneous proppant pack 4 has the dual purpose of propping open the subterranean fractures 8 and reducing the viscosity of the viscosified fracture fluid 1.

Proppant compositions and methods for using same are disclosed herein. In particular, a proppant composition for use in hydraulic fracturing is disclosed herein. The proppant composition can contain a plurality of particulates and at least one particulate of the plurality of particulates containing a chemical treatment agent. The at least one particulate having a long term permeability measured in accordance with ISO 13503-5 at 7,500 psi of at least about 10 D. The at least one chemical treatment agent can separate from the at least one particulate when located inside a fracture of a subterranean formation after a period of time.

A composition for dissolving drilling mud including barite particles and a polymer includes an enzyme capable of reacting with the polymer; a chelating agent capable of dissolving the barite particles; and a catalyst capable of promoting a reaction between the chelating agent and the barite particles.

Disclosed herein are compositions and methods for delaying crosslinking in injectable compositions for hydraulic fracturing and related applications. The compositions and methods are effective in injectable compositions comprising or substantially excluding dissolved reactive species. The compositions and methods provide delayed crosslinking at high temperatures and pressures, such as those encountered by hydraulic fracturing compositions injected into subterranean environments. Compositions include injectable solutions comprising a competing agent that is the reaction product of a dialdehyde having 2 to 4 carbon atoms with a non-polymeric cis-hydroxyl compound. Also provided are methods of making and using delayed-crosslinking compositions comprising crosslinker compositions containing zirconium complexes and the competing agents.

The present invention relates to a composition for dissolving an oil-based filter cake in a wellbore, and a single-step method of use. The composition comprises a chelating agent, a converting agent, a polymer removal agent, a mutual solvent, and a surfactant. The present invention also relates to a multi-step method of dissolving an oil-based filter cake using similar components. Both single-step and multistep methods may be used to dissolve oil-based filter cakes comprising barite as a weighting material.

The invention relates to a process for enhanced hydrocarbon recovery in a subterranean formation, in particular enhanced crude oil recovery, using at least one water-soluble terpolymer in aqueous solution, said water-soluble terpolymer being a partially hydrolysed polyacrylamide of formula (I)

##STR00001##

wherein X is an alkali metal cation chosen from sodium, lithium or potassium, or an ammonium cation NH.sub.4.sup.+;

the coefficients a, b and c being defined in the following way:

[00001]$\frac{a}{a+b+c}$

is greater than or equal to 0.50, preferably between 0.5 and 0.8, limits included,

[00002]$\frac{b}{a+b+c}$

is less than 0.50, preferably between 0.1 and 0.4, limits included,

[00003]$\frac{c}{a+b+c}$

is between 0.01 and 0.20, preferably between 0.02 and 0.15, limits included, all of the ratios having a sum equal to 1.