Abstract: A method of stimulating petroleum production includes introducing a fracturing fluid into a petroleum formation, thereby creating at least one fracture to stimulate the petroleum production. The fracturing fluid is introduced into the petroleum formation at a pressure above the breakdown pressure of the formation. The fracturing fluid includes a plurality of proppants each including a proppant particle and a coating. The coating includes a hydrophobic coating, a cross-linked hydrogel, or both. From 1 to 50 wt. % of the plurality of proppants includes micro proppants having a particle size ranging from 0.5 to 150 ?m, and from 50 to 99 wt. % of the plurality of proppants includes macro proppants having a particle size of 100 mesh or greater.

Abstract: Aqueous well treatment fluids especially suited for use in far field diversion in low viscosity carrier fluids comprise water, a friction reducer, and a diverter. The diverter comprises dissolvable particulates and proppants. The dissolvable particulates have a specific gravity of from about 0.9 to about 1.6 and a particle size of about 50 mesh or less. The proppants have a specific gravity of from about 0.9 to about 1.4 and a particle size of from about 20 to about 100 mesh. The dissolvable particulates have a higher specific gravity and a smaller particle size than the proppant.

Abstract: A system, composition and method for controlling vertical growth direction (up and down) of one or more fractures and/or rate of growth of one or more fractures by varying the specific gravity of one or more slurries or fluids being pumped into a well during a tracking operation.

Abstract: A gun tube for a downhole perforating gun assembly includes a body having a cavity and one or more weights in the cavity. Gravity acts on the weights, which causes the tube body to rotate around its longitudinal axis so the weights are adjacent the lower part of the wellbore in which the gun assembly is positioned when oriented horizontally. This position shape charges in the gun tube in a desired position prior to the shape charges being fired. The gun tube may also include one or more end connectors with electrical contacts having a first, extended position, and a second, contracted position, and/or end connectors that can be assembled by hand without the use of tools.

Abstract: A frac sleeve system includes a well casing with a tubular wall having a frac port defined there through for hydraulic fracturing. A sleeve within the well casing includes a sleeve body. The sleeve is mounted for axial movement relative to the tubular wall of the well casing among three positions including: a closed position in which the sleeve body blocks the frac port, a frac position in which the sleeve body clears the frac port so the frac port is open for hydraulic fracturing there through, and a production position in which the sleeve at least partially blocks the frac port.

Abstract: Process of fracturing subterranean, oil-and/or gas-bearing formations by injecting an aqueous fracturing fluid into a wellbore at a rate and pressure sufficient to penetrate into the formation, and to initiate or extend fractures in the formation, wherein the aqueous fracturing fluid is obtained by mixing at least an aqueous base fluid and an aqueous polyacrylamide concentrate having a concentration of 3.1 to 14.9% by weight of polyacrylamides, relating to the total of all components of the aqueous polyacrylamide concentrate, and wherein at least a part of the aqueous fracturing fluid injected additionally comprises a proppant.

Abstract: Providing electric power distribution for fracturing operations comprising receiving, at a transport, electric power from a mobile source of electricity at a first voltage level and supplying, from the transport, the electric power to a fracturing pump transport at the first voltage level using only a first, single cable connection. The first voltage level falls within a range of 1,000 V to 35 kilovolts. The transport also supplies electric power to a second transport at the first voltage level using only a second, single cable connection.

Abstract: A system for delivering hydraulic fracturing fluid to a wellbore is provided. The system includes a first frac tree connected to a first wellbore and a second frac tree connected to second wellbore. The system further includes a zipper module and a first single straight-line connection between the zipper module and the first frac tree. The system also includes a second single straight-line connection between the first frac tree and the second frac tree.

Abstract: Processes are provided for conformance control in the production of hydrocarbons from reservoirs, involving the distribution of mobilizing injection fluids into a formation through a number of injection fluid distribution points spaced apart along an injection well. The volume and/or position of mobilizing fluid outflows at the distribution points is adjusted based on criteria that include selected reservoir parameters measured at spatially distributed measurement points in the reservoir. An operational system is provided so that these measurements provide a proxy for recovery chamber conformance.

Abstract: A system and method for independent control of simultaneous fracturing for multiple wellbores is disclosed. In certain embodiments, a first clean pumping unit and a first dirty pumping unit are fluidically coupled to a first wellbore, wherein the first clean pumping unit pumps a first fluid to the first wellbore and the second clean pumping unit pumps a second fluid to the first wellbore. In certain embodiments, a second clean pumping unit and a second dirty pumping unit are fluidically coupled to a second wellbore, wherein the second clean pumping unit pumps the first fluid to the second wellbore and the second dirty pumping unit pumps. In certain embodiments, a controller controls a pumping rate of at least one of the first clean pumping unit and the first dirty pumping unit based on a desired parameter of a combined fluid pumped to the first wellbore.

Abstract: A downhole system includes a lower completion having at least one tubular including a first end and a second end terminating at a shoe. The at least one tubular defining a flow path. A packer is arranged at the first end. A fluid loss control valve (FLCV) is arranged between the packer and the shoe. A screen system is arranged between the FLCV and the shoe. The screen system includes a screen and a non-mechanically operated flow control valve that selectively isolates the flow path from formation fluids passing through the screen. A wellbore clean out string is insertable into the lower completion. The wellbore clean out string includes a selectively activated casing cleaner and a setting tool. The selectively activated casing cleaner is spaced from the setting tool.

Abstract: A multi-blender system for blending liquid and solid particulates together to prepare a fracturing fluid, the blender system can include a plurality of independently operable blender units each having components that can operate with either blender unit. Each component may be a modular blender component mounted to respective independent frames. The independent frames are configured to be independently removable, replaceable and movable to multiple positions in the blender system. In some aspects the multi-blender system can operate at different sand concentrations, instantaneously adjust flow rate to one or more of the components in either blender unit, provide control redundancy, and may continue to operate despite a failure of one of the major components.

Abstract: The present disclosure relates generally to well operations. The present disclosure relates more particularly to a systems and methods for independently and/or simultaneously treating multiple wells from a centralized location using a split flow pumping system configuration. The split flow pumping system configuration may comprise one or more blenders, one or more boost pumps, a pumping system comprising one or more pumps, a component storage system, and a fluid storage system for treatment of two or more wells using two or more treatment compositions. The split flow pumping system configuration may comprise one or more controllers for controlling the one or more blenders, the one or more boost pumps, the pumping system comprising one or more pumps, the component storage system, and the fluid storage system.

Abstract: A system detects an acoustic-wave-producing downhole event associated with a pipe at an uphole location in the presence of surface noise. The system comprises: a first plurality of acoustic sensors located a first axial position along the pipe and oriented symmetrically about the pipe axis; and a second plurality of acoustic sensors located a second axial position along the pipe and oriented symmetrically about the pipe axis, the second axial position spaced apart from the first axial position. A processor is connected to receive the signals from the first and second pluralities of sensors and configured to process the sensor signals to thereby produce an output signal. The processor is configured to adjust the digital processing, based on the sensor signals, to minimize a contribution of the surface noise to the output signal.

Abstract: Hydraulic fracturing a subterranean formation with frac fluid, the hydraulic fracturing including complex shear fracturing of the subterranean formation. The technique includes determining an amount of the complex shear fracturing occurring, and adjusting operating parameters of the hydraulic fracturing to increase the complex shear fracturing occurring. The amount may consider fracture surface area. The adjusting may consider resonant frequency of the subterranean formation rock being fractured. The complex shear fracturing may assist with diffusion production. The techniques may include a non-transitory, computer-readable medium having instructions executable by a processor of a computing device to facilitate the aforementioned actions.

Abstract: A downhole well tool assembly can include a perforator and a selectively openable and closable perforation plug discharge port. A method of perforating and treating multiple formation zones of a well in a single trip of a downhole well tool assembly into the well can include positioning the downhole well tool assembly at a zone, closing a perforation plug discharge port of the downhole well tool assembly, perforating the zone, treating the zone, opening the perforation plug discharge port, deploying perforation plugs into the well via the perforation plug discharge port, plugging perforations in the zone with the perforation plugs, positioning the downhole well tool assembly at a subsequent zone, closing the perforation plug discharge port, perforating the subsequent zone, and treating the subsequent zone.

Abstract: A hydraulic fracturing plan executable by a hydraulic fracturing system to hydraulically fracture a plurality of oil and gas wells. In one or more embodiments, the execution of the hydraulic fracturing plan implements the following steps: communicating fluid to a first well via a manifold and a first valve, the first valve being associated with both the manifold and the first well; and, in response to determining that the fluid communicated via the manifold has satisfied one or more conditions: opening a second valve; communicating fluid to a second well via the second valve; and closing the first valve after opening the second valve.

Abstract: Disclosed are systems and methods for detecting the beginning of a flush volume. A blended fluid is output by a fluid blending apparatus and pumped into a wellbore. The blended fluid transitions from a first composition to a second composition. A blending signal comprising time-varying data relating to characteristics of the blending apparatus or measured from sensors associated with the blending apparatus is received. Based on a first portion of the blending signal corresponding to the first composition, a calibration profile is generated. Based on the calibration profile and a second portion of the blending signal corresponding to the second composition, a transition indicator corresponding to a change in the blended fluid from the first composition to the second composition is determined. Based on the transition indicator, a flush signal indicating the beginning of a flush volume being output by the blending apparatus and pumped into the wellbore is generated.

Abstract: Aspects of the disclosure relate to flexible wellhead connection systems, apparatus, methods, and associated components thereof. The aspects include a rotatable joint. In one example, the rotatable joint includes a swivel. In one example, the flexible wellhead connection systems, apparatus, and methods are used to connect wellheads to one or more of fluid sources and/or instrumentation skids.

Abstract: Systems and methods for managing flowback fluids produced during a flowback process in a well are provided. The system includes a well formed in a target zone in a hydrocarbon reservoir, where the well also extends to a disposal zone. The system also includes a check valve or zonal isolation systems. The method includes selecting a disposal zone, directing the formation of a well extending through a target zone and a disposal zone, transporting the flowback fluid from the target zone to the disposal zone during the flowback process, and selectively plugging the well near the disposal zone to prevent migration of the flowback fluid.

Abstract: The present invention relates to a downhole apparatus and a valve arrangement for a downhole apparatus having a tubular body having first and second ports in a wall thereof; and a method of operating a valve arrangement of a downhole apparatus. The valve arrangement has at least one locked configuration and the first port provides fluid communication with a tool or a device which is a sand control element having at least one fluid deformable device. The present invention also provides a method of setting a sand control completion, extending the sand control filter element thereof to a wellbore surface and isolating the reservoir from an upper portion of the wellbore.

Abstract: A fracturing system can include a fracturing manifold coupled to a plurality of fracturing trees. The fracturing manifold may include adjustment joints that enable adjustment of the length of the fracturing manifold. The fracturing manifold can also include pivot joints that allow angular displacement of portions of the fracturing manifold with respect to other portions. The adjustment and pivot joints can accommodate spacing and elevation differences between the fracturing trees.

Abstract: A method for performing a fracturing operation in a subterranean formation of a field. The method includes obtaining, during the fracturing operation, distributed optical fiber data from a downhole sensor of a treatment well in the subterranean formation, and determining, based on the distributed optical fiber data, an active perforation location from a number of pre-determined perforation locations of the treatment well. The active perforation location is a location of fluid flow into the subterranean formation during the fracturing operation. The method further includes generating, based at least on the active perforation location, a fracturing model for the subterranean formation, and performing, based on the fracturing model, modeling of the fracturing operation to generate a modeling result.

Abstract: A system may include: a source of water fluidically coupled to a fracturing blender; water testing equipment disposed between the source of water and the fracturing blender wherein the water testing equipment is operable to measure at least one property of the source of water; a plurality of friction reducing polymers operable to be added to the fracturing blender; and a control system comprising: at least one processor; and a memory coupled to the processor to provide software that configures the processor to receive an input signal from the water testing equipment and select at least one of the plurality of friction reducing polymers.

Abstract: Systems and methods for identifying a status of components of hydraulic fracturing units including a prime mover and a hydraulic fracturing pump to pump fracturing fluid into a wellhead via a manifold may include a diagnostic control assembly. The diagnostic control assembly may include sensors associated with the hydraulic fracturing units or the manifold, and a supervisory control unit to determine whether the sensors are generating signals outside a calibration range, determine whether a fluid parameter associated with an auxiliary system of the hydraulic fracturing units is indicative of a fluid-related problem, determine whether lubrication associated with the prime mover, the hydraulic fracturing pump, or a transmission of the hydraulic fracturing units has a lubrication fluid temperature greater than a maximum lubrication temperature, or determine an extent to which a heat exchanger assembly associated with the hydraulic fracturing units is cooling fluid passing through the heat exchanger assembly.

Abstract: Provided is a diagnostic wellbore testing method that includes forming a diagnostic wellbore in a subterranean zone including one or more formations. The wellbore extends through a portion of a formation having a maximum horizontal stress extending in a first direction and a minimum horizontal stress extending in a second direction perpendicular to the first direction. The method also includes forming a pair of notches on a circumference of the wellbore. The pair of notches are formed diametrically opposite each other. The method also includes applying fluidic pressure to the wellbore at the pair of notches in the second direction while avoiding applying fluidic pressure in the first direction. Fractures propagate from the pair of notches responsive to the fluidic pressure. The method also includes measuring a closure pressure of the wellbore, and providing the closure pressure as the maximum horizontal stress of the formation.

Abstract: Provided is an interval control valve. The interval control valve, in one aspect, includes a tubular housing, the tubular housing having one or more openings extending there through, and a sliding sleeve positioned within the tubular, the sliding sleeve configured to move between a closed position closing a fluid path between the one or more opening and an interior of the tubular housing, and an open position opening the fluid path between the one or more openings and the interior of the tubular housing. The interval control valve according to this aspect additionally includes a tubular overlapping with the sliding sleeve, the sliding sleeve and the tubular defining an overlapping space, and an expanded metal joint located in at least a portion of the overlapping space, the expanded metal joint comprising a metal that has expanded in response to hydrolysis.

Abstract: A method of treating a highly permeable subterranean formation that is penetrated by a wellbore to form a frac pack in the formation adjacent to a desired wellbore interval is provided. The method comprises (a) injecting a first high efficiency fracturing fluid into the formation to form a fracture in the formation that propagates from a near-wellbore region of the formation into a far-field region of the formation. Thereafter, high strength proppant is placed in a portion of the fracture in the near-wellbore region of the formation, and low strength proppant is placed in a portion of the fracture near the far-field region of the formation using low viscosity fluids. Subsequently, a high strength proppant is squeezed into a portion of the fracture in the near-wellbore region of the formation to assure that the fracture is completely packed.

Abstract: System and methods of controlling diversion for stimulation treatments in real time are provided. Input parameters are determined for a stimulation treatment being performed along a wellbore within a subsurface formation. The input parameters include selected treatment design parameters and formation parameters. A step-down analysis is performed to identify friction components of a total fracture entry friction affecting near-wellbore pressure loss during the stimulation treatment. Efficiency parameters are determined for a diversion phase of the stimulation treatment to be performed along a portion of the wellbore, based on the input parameters and the friction components. An amount of diverter to be injected during the diversion phase of the stimulation treatment is calculated based at least partly on the efficiency parameters.

Abstract: The disclosure provides for a method of enhancing heat transfer between an injection fluid and a subterranean formation. The method comprises of introducing a fracturing fluid into a first wellbore and a second wellbore comprising a plurality of electro-conductive proppants and electrically controlled propellant, wherein the fracturing fluid is introduced at or above a pressure sufficient to create or enhance one or more primary fractures in the subterranean formation. The method further comprises of applying an electrical current, wherein the plurality of electro-conductive proppants is operable to receive the electrical current and igniting the electrically controlled propellant through application of the electrical current from the plurality of electro-conductive proppants to rubblize the subterranean formation.

Abstract: An injection pumping system is used to generate pressure pulses in a wellbore to create pressure spikes for stimulation treatment of the wellbore. An initial pressure pulse is generated with a known travel time from the surface to a termination point and back to a specified location within the wellbore. A subsequent pressure pulse with a known travel time from the surface to the specified location can be generated to collide with the initial pressure pulse at the specified location. Knowing the speed of sound throughout the wellbore allows for an accurate calculation of the required travel times for each of the pressure pulses. Multiple sections of the wellbore can be treated preferentially and independently without requiring multiple runs of a perforating tool as the pressure pulses can be manipulated to collide at different locations throughout the wellbore based on the known travel times.

Abstract: Embodiments include a hydraulic fracturing system for fracturing a subterranean formation. The system includes an electric pump, arranged on a first support structure, the electric pump coupled to a well associated with the subterranean formation and powered by at least one electric motor, and configured to pump fluid into a wellbore associated with the well at a high pressure so that the fluid passes from the wellbore into the subterranean formation and fractures the subterranean formation. The system also includes support equipment, arranged on a second support structure, electrically coupled to the electric pump, wherein the support equipment includes at least a transformer for distributing power to the electric pump, the power being received from at least one generator at a voltage higher than an operating voltage of the electric pump.

Abstract: Embodiments of the present disclosure are directed to a method of producing a viscoelastic surfactant (VES) fluid, the VES fluid comprising desulfated seawater. The method of producing the VES fluid comprises adding an alkaline earth metal halide to seawater to produce a sulfate precipitate. The method further comprises removing the sulfate precipitate to produce the desulfated water. The method further comprises adding a VES and one or more of a nanoparticle viscosity modifier or a polymeric modifier to the desulfated seawater. Other embodiments are directed to VES fluids that maintain a viscosity greater than 10 cP at temperatures above 250° F.

Abstract: A well-logging system includes a downhole tool coupled to a cable. The downhole tool may measure physical parameters of a wellbore via a first plurality of sensors. The well-logging system may include wellbore equipment including a winch. The winch may traverse the downhole tool through the wellbore by spooling or unspooling the cable. The well-logging system may also include a second plurality of sensors that may measure operational parameters of the wellbore equipment. The well-logging system may further include an automation controller that is communicatively coupled to the first plurality of sensors and the second plurality of sensors. A set of defined operating instructions may be prepared during the assembly of the job. The automation controller may control the wellbore equipment based at least in part on feedback from the first plurality of sensors, feedback from the second plurality of sensors, and the defined operating instructions.

Abstract: System, methods, and devices for simultaneously fracturing a target formation and an adjacent secondary formation are disclosed. The simultaneous fracturing operations interfere with each other to form in-situ dynamic barriers. The in-situ barriers prevent acid from the fracturing treatment in the target formation from invading the secondary formation and, in some instances, sealing formation rock at the location of the in-situ barrier to prevent or reduce water movement from the secondary formation into the primary formation.

Abstract: Completion systems, methods to produce differential flow rate through a port during different well operations, and methods to reduce proppant flow back are disclosed. A completion system includes a tubular extending through a wellbore and having a first port and a second port. The completion system also includes a cover disposed along an interior of the tubular and configured to cover the first port and the second port while the cover is in a first position and is configured to uncover the first port and the second port while the cover is in a second position. The completion system further includes a valve disposed along the tubular and configured to differentially restrict fluid flow through the first port during different well operations.

Abstract: A hydraulic fracturing plan executable by a hydraulic fracturing system to hydraulically fracture a plurality of oil and gas wells.

Abstract: The present invention provides a method and system for providing on-site electrical power to a fracturing operation, and an electrically powered fracturing system. Natural gas can be used to drive a turbine generator in the production of electrical power. A scalable, electrically powered fracturing fleet is provided to pump fluids for the fracturing operation, obviating the need for a constant supply of diesel fuel to the site and reducing the site footprint and infrastructure required for the fracturing operation, when compared with conventional systems.

Abstract: A dispersion of capsules in critical or supercritical carbon dioxide is provided. The capsules include an aqueous solution encapsulated by zeolite-templated carbon particles. Also provided is a method of making a dispersion of aqueous solution capsules. The method includes providing a medium of critical or supercritical carbon dioxide, introducing the aqueous solution into the critical or supercritical carbon dioxide medium, and introducing a zeolite-templated carbon particle into the critical or supercritical carbon dioxide medium. Associated methods of using the disclosed dispersions in hydrocarbon-bearing formations are also provided.

Abstract: An assembly for perforating a downhole formation includes a perforating gun, coupled to a downhole conveyance system, the perforating gun including an explosive charge and an uphole contact. The assembly also includes a tandem, coupled to the perforating gun proximate the uphole contact, the tandem including a cartridge assembly communicatively coupled to the downhole contact and a primary igniter communicatively coupled to the cartridge assembly. The assembly further includes an intermediate sub, coupled to the tandem opposite the perforating gun, the intermediate sub receiving at least a portion of the primary igniter, the intermediate sub having a fuse and secondary igniter. The assembly also includes a setting tool coupled to the intermediate sub, the setting tool receiving a setting signal via the secondary igniter.

Abstract: Aspects of the subject technology relate to systems and methods for pumping a wellbore with a pump operating in a damage avoidance mode during a hydraulic fracturing job. A fluid pump of known operating pump capacity measurable in barrels per minute is selected. The pump is fluidly connected with each of a cased wellbore in a subterranean formation for providing fracturing fluid to the wellbore. The wellbore has at least one perforation through a casing of the wellbore that has a known rate range within which fracturing fluid is required to successfully fracture the subterranean formation outside the perforation through the perforation. The pump is configured to provide fracturing fluid to each perforation within the known rate range of the respective perforation to successfully fracture the subterranean formation outside of the perforation while operating the pump in a damage avoidance mode.

Abstract: Systems and methods for controlling fracturing operations include monitoring pressure within a monitor well poroelastically couplable to an active well. In response to pressure changes observed in the monitor well, operational parameters of the fracturing operation are modified to, among other things, encourage or inhibit fracture initiation and propagation. For example, modifications to properties of the fracturing fluid, modification to pumping parameters, rate cycling, and diversion operations may each be undertaken in response to observed pressure changes within the monitor well. Single-well applications are also provided in which pressure measurements are obtained from an isolated section of a well poroelastically couplable to an uphole section of the same well. The pressure measurements are subsequently used to control fracturing operations of the uphole section.

Abstract: A modular pumping pad skid may include a base with one or more high pressure fluid conduits and one or more low pressure conduits. Additionally, two or more pumps may be removably fixed to the base, and fluidly connected to the high pressure fluid conduits and the low pressure conduits.

Abstract: A method for the simultaneous removal of filter cake from a wellbore and fracturing of the wellbore using a mixture including a chelating agent and a thermochemical. The method including feeding a mixture into the wellbore, contacting the filter cake with the mixture, reacting the chelating agent and the thermochemical to produce heat and pressure, removing the filter cake from the wellbore, and creating microfractures in the wellbore using pressure produced from the reacting.

Abstract: Provided herein are methods of increasing production from a hydrocarbon containing formation by adding a proppant to the formation, wherein a treatment fluid comprising a colloidal silica nanoparticle is added to the formation before, during or after the time the proppant is added to the formation.

Abstract: Methods for enhancing the conductivity of fractures in a subterranean formation using electrically controlled propellants are provided. In some embodiments, the methods comprise: introducing an electrically controlled propellant into one or more secondary boreholes in a subterranean formation near a main well bore that penetrates the subterranean formation; igniting the electrically controlled propellant in the secondary boreholes, whereby at least a portion of the region of the subterranean formation near the secondary borehole is at least partially ruptured by the ignition of the electrically controlled propellant in the secondary boreholes; and introducing a fracturing fluid into the main wellbore at or above a pressure sufficient to create or enhance at least one primary fracture in the subterranean formation that extends into at least a portion of the ruptured region of the subterranean formation.

Abstract: Apparatuses, systems, and methods for performing wellbore completion and production operations in a subterranean formation are provided. In some embodiments, the methods include: disposing an electronic initiator sleeve within a closed wellbore penetrating at least a portion of a subterranean formation, wherein the electronic initiator sleeve comprises: a housing having at least one port, a sleeve in a closed position, an actuator, and at least one sensor; increasing fluid pressure within the closed wellbore for a period of time, wherein the sleeve remains in the closed position during the period of time; detecting a signal with the at least one sensor; and actuating the actuator in response to the signal to transition the sleeve from the closed position to an open position.

Abstract: A system and a method for cooling a prime mover and lube oil, comprising: a prime mover configured to drive a pump with a motor shaft; a prime mover cooling assembly that encases the prime mover, wherein the prime mover cooling assembly comprises: an air intake and an exhaust ventilator mounted above the prime mover; and a lube oil cooling assembly mounted above the prime mover, wherein the lube oil cooling assembly cools lube oil circulating within the pump and is mounted above the prime mover such that the lube oil cooling assembly does not hang off one or more sides of the prime mover and prime mover cooling assembly.

Abstract: A wellbore servicing fluid comprising (a) a cationic formation stabilizer having (i) a molecular weight in a range of from equal to or greater than 0.05 to equal to or less than 2.0 kiloDaltons (kDa), or (ii) cationic charge functional groups of greater than 2 to equal to or less than 5 cationic charges per molecule, or (iii) both (i) and (ii), (b) an anionic friction reducer, and (c) an aqueous fluid.

Abstract: The invention relates to the completion of hydrocarbon wells using acid. It is known to create cavities in the formation using acid, which then collapse to leave a highly permeable region for production of hydrocarbons. An issue with this technique can be that the wellbore/tubing adjacent the cavity is damaged. The invention involves passing thin conduits through the formation transversely of the main wellbore, through which conduits acid is delivered to create unstable cavities at a distance from the main wellbore thereby stimulating production without risking instability of the main wellbore.