Abstract: A method of heterogeneous proppant placement in a subterranean fracture is disclosed. The method comprises injecting well treatment fluid including proppant (16) and proppant-spacing filler material (18) through a wellbore (10) into the fracture (20), heterogeneously placing the proppant in the fracture in a plurality of proppant clusters or islands (22) spaced apart by the material (24), and removing the filler material (24) to form open channels (26) around the pillars (28). The filler material can be dissolvable particles, initially acting as a consolidator during placement of the proppant in the fracture, and later dissolving to leave flow channels between the proppant pillars. The well treatment fluid can include extrametrical materials to provide reinforcement and consolidation of the proppant and, additionally or alternatively, to inhibit settling of the proppant in the treatment fluid.

Abstract: A technique facilitates the study of complex fracture networks. A slot manifold is constructed with a system of branched thin channels, e.g. slots, which are joined at intersections. Fluid is flowed through the system of branched thin channels and through an intersection or intersections joining the channels in a manner which enables evaluation of fluid flow. A flow distribution device is used to allow or block flow of the fluid along specific branches of the system of branched thin channels to facilitate evaluation of fluid flow as a fluid moves through various angular changes and/or flow gap width changes from one channel to another.

Abstract: Methods of selection of materials that are used as a proppant for HPP fracturing treatments, also the procedure for the design of HPP treatment.

Abstract: A method is given for fracturing a formation, in particular far-field in a tight formation, in which at least a portion of the proppant is crushable in situ at some point during pumping, during fracture closure, or at higher stresses experienced later during fracture closure. The closure stress or hydrostatic stress is estimated, then a proppant is selected that is at least partially crushable at that closure stress, and then the fracturing treatment is performed with at least a portion of the total proppant being the selected crushable proppant.

Abstract: A technique facilitates the study of complex fracture networks. A slot manifold is constructed with a system of branched thin channels, e.g. slots, which are joined at intersections. Fluid is flowed through the system of branched thin channels and through an intersection or intersections joining the channels in a manner which enables evaluation of fluid flow. A flow distribution device is used to allow or block flow of the fluid along specific branches of the system of branched thin channels to facilitate evaluation of fluid flow as a fluid moves through various angular changes and/or flow gap width changes from one channel to another.

Abstract: A method is given for fracturing a formation, in particular far-field in a tight formation, in which at least a portion of the proppant is crushable in situ at some point during pumping, during fracture closure, or at higher stresses experienced later during fracture closure. The closure stress or hydrostatic stress is estimated, then a proppant is selected that is at least partially crushable at that closure stress, and then the fracturing treatment is performed with at least a portion of the total proppant being the selected crushable proppant.

Abstract: A method is given for heterogeneous proppant placement in fracturing by in situ aggregation of fine mesh proppant particulates or other materials such as fibers in a subterranean fracture. A polymer is injected into a subterranean formation and is subsequently subjected to a chemical reaction, for example hydrolysis, under downhole conditions, which leads to formation of either a cationic or an anionic polyelectrolyte. Alternatively, the polyelectrolyte is synthesized downhole by, for example, a Hofmann degradation or a Mannich reaction. The polyelectrolyte acts as a flocculant and provides aggregation of solid particulates such as sand, mica, silica flour, ceramics and the like, which leads to formation of proppant micropillars deep in the fracture. Methods of aggregation of fibers to enhance bridging, and other applications of controlled flocculation are also given.

Abstract: A method is given for treating a wellbore in a subterranean formation by hydraulic fracturing, slickwater fracturing, gravel packing, and the like, by using plate-like materials as some or all of the proppant or gravel. The plate-like materials are particularly useful in complex fracture systems, for example in shales. They may be used as from about 20 to about 100% of the proppant. Relative to conventional proppants, plate-like proppants demonstrate (a) enhanced crush resistance of the proppant due to better stress distribution among proppant particles, (b) diminished proppant embedment into formation fracture faces due to the greater contact surface area of proppant particles with the formation, (c) better proppant transport due to lower proppant settling rates, (d) deeper penetration into branched and fine fracture networks, and (e) enhanced proppant flowback control. Preferred plate-like proppants are layered rocks and minerals; most preferred is mica.

Abstract: A method of heterogeneous proppant placement in a subterranean fracture is disclosed. The method comprises injecting well treatment fluid including proppant (16) and proppant-spacing filler material (18) through a wellbore (10) into the fracture (20), heterogeneously placing the proppant in the fracture in a plurality of proppant clusters or islands (22) spaced apart by the material (24), and removing the filler material (24) to form open channels (26) around the pillars (28). The filler material can be dissolvable particles, initially acting as a consolidator during placement of the proppant in the fracture, and later dissolving to leave flow channels between the proppant pillars. The well treatment fluid can include extrametrical materials to provide reinforcement and consolidation of the proppant and, additionally or alternatively, to inhibit settling of the proppant in the treatment fluid.

Abstract: A method of heterogeneous proppant placement in a subterranean fracture is disclosed. The method comprises injecting well treatment fluid including proppant (16) and proppant-spacing filler material (18) through a wellbore (10) into the fracture (20), heterogeneously placing the proppant in the fracture in a plurality of proppant clusters or islands (22) spaced apart by the material (24), and removing the filler material (24) to form open channels (26) around the pillars (28). The filler material can be dissolvable particles, initially acting as a consolidator during placement of the proppant in the fracture, and later dissolving to leave flow channels between the proppant pillars. The well treatment fluid can include extrametrical materials to provide reinforcement and consolidation of the proppant and, additionally or alternatively, to inhibit settling of the proppant in the treatment fluid.

Abstract: A method is given for treating a wellbore in a subterranean formation by hydraulic fracturing, slickwater fracturing, gravel packing, and the like, by using plate-like materials as some or all of the proppant or gravel. The plate-like materials are particularly useful in complex fracture systems, for example in shales. They may be used as from about 20 to about 100% of the proppant. Relative to conventional proppants, plate-like proppants demonstrate (a) enhanced crush resistance of the proppant due to better stress distribution among proppant particles, (b) diminished proppant embedment into formation fracture faces due to the greater contact surface area of proppant particles with the formation, (c) better proppant transport due to lower proppant settling rates, (d) deeper penetration into branched and fine fracture networks, and (e) enhanced proppant flowback control. Preferred plate-like proppants are layered rocks and minerals; most preferred is mica.

Abstract: Embodiments of hydraulic fracturing methods disclosed herein use fine mesh proppant. In one embodiment the method is used to fracture a low permeability formation. In one embodiment the method uses flocculation to improve conductivity of a fracture. In one embodiment fluid flow through the fine mesh proppant in the fracture creates a network of connected channels to improve the fracture conductivity.

Abstract: A method is given for diverting injected slickwater in a hydraulic fracturing treatment. The diversion fluid is preferably a substantially proppant free viscous fluid that causes a net pressure increase and plugging of some of the microfractures in the initial fracture system created, which induces formation of supplementary microfractures connected to the initial fracture network and in-creases the contact area with the formation rock. The method generates a greater fracture network complexity and thus a higher contact area with the reservoir during a single treatment cycle.

Abstract: A method is given for inducing heterogeneous proppant placement in a hydraulic fracture in a subterranean formation by causing proppant aggregation through a gel phase transition or chemical transformation in the proppant carrier fluid. Proppant aggregation may be induced by causing or allowing syneresis of the polymer gel that viscosifies the fluid; formation of a polyelectrolyte complex from cationic and anionic polymers included in or created in, the fluid; and by increasing the temperature of the fluid above the critical solution temperature of a polymer in the fluid. The proppant carrier fluid may be formulated such that these transformations occur naturally during or after proppant injection, and the transformations may be chemically triggered or delayed.

Abstract: A method is given for heterogeneous proppant placement in fracturing by in situ aggregation of fine mesh proppant particulates or other materials such as fibers in a subterranean fracture. A polymer is injected into a subterranean formation and is subsequently subjected to a chemical reaction, for example hydrolysis, under downhole conditions, which leads to formation of either a cationic or an anionic polyelectrolyte. Alternatively, the polyelectrolyte is synthesized downhole by, for example, a Hofmann degradation or a Mannich reaction. The polyelectrolyte acts as a flocculant and provides aggregation of solid particulates such as sand, mica, silica flour, ceramics and the like, which leads to formation of proppant micropillars deep in the fracture. Methods of aggregation of fibers to enhance bridging, and other applications of controlled flocculation are also given.

Abstract: A method is given for fracturing a formation, in particular far-field in a tight formation, in which at least a portion of the proppant is crushable in situ at some point during pumping, during fracture closure, or at higher Fluid flow stresses experienced later during fracture closure. The closure stress or hydrostatic stress is estimated, then a proppant is selected that is at least partially crushable at that closure stress, and then the fracturing treatment is performed with at least a portion of the total proppant being the selected crushable proppant.

Abstract: A method of heterogeneous proppant placement in a subterranean fracture is disclosed. The method comprises injecting well treatment fluid including proppant (16) and proppant-spacing filler material (18) through a wellbore (10) into the fracture (20), heterogeneously placing the proppant in the fracture in a plurality of proppant clusters or islands (22) spaced apart by the material (24), and removing the filler material (24) to form open channels (26) around the pillars (28). The filler material can be dissolvable particles, initially acting as a consolidator during placement of the proppant in the fracture, and later dissolving to leave flow channels between the proppant pillars. The well treatment fluid can include extrametrical materials to provide reinforcement and consolidation of the proppant and, additionally or alternatively, to inhibit settling of the proppant in the treatment fluid.