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US-12624620-B1 - Hydraulic fracturing system and method using a downhole pulsing tool

US12624620B1US 12624620 B1US12624620 B1US 12624620B1US-12624620-B1

Abstract

A downhole hydraulic fracturing system and method utilizing downhole pressure pulsing to enhance fracture propagation, proppant transport, and reservoir permeability. The system employs a hybrid fracturing approach that integrates conventional hydraulic fracturing with downhole pulse hydraulic fracturing. This hybrid technique reduces surface energy demands, enhances fracture initiation, increases fracture density, and improves proppant distribution, thereby maximizing reservoir permeability and overall production efficiency. The system is configured to include: a mechanism that enables real-time, surface-controlled adjustment of pulse intensity; a downhole system capable of generating self-sustained pulsing independent of tubular movement, a downhole sensor system configured to detect, record, and analyze downhole fluid pressure and other critical parameters and additional embodiments that enhance energy transfer efficiency, increase fracture complexity, and optimize proppant transport.

Inventors

  • Ian Allahar

Assignees

  • Ian Allahar

Dates

Publication Date
20260512
Application Date
20250225

Claims (6)

  1. 1 . A downhole reservoir stimulation system comprising of: a) a downhole pulsing tool positioned within a wellbore, configured to generate multiple, self-sustained cyclic pressure pulses autonomously and independently of drill string tubular movements, b) a surface-controlled pulse adjustment mechanism configured to dynamically adjust pulse intensity, frequency, and duration in real-time based on downhole fluid pressure data and formation responses, c) a downhole pressure sensor integrated within the pulsing tool, configured to continuously monitor pulse interactions, the formation responses, pressure decay trends, and stimulated reservoir volume (SRV), d) an injector tool coupled below the downhole pulsing tool, comprising of specialized nozzles configured to remain closed until a predefined differential pressure is reached, ensuring controlled energy release and optimized proppant distribution into a subsurface formation; and e) an anchoring mechanism comprising of expandable blocks activated by at least one of an RFID tag recognition mechanism or ball drop mechanism, configured to securely anchor the downhole pulsing tool to a wellbore casing.
  2. 2 . The downhole reservoir stimulation system of claim 1 , further comprising: a mechanical energy storage mechanism including at least one of a spring-loaded assembly or a compressed gas chamber, configured to autonomously store and release mechanical energy, maintaining an oscillatory feedback loop for continuous cyclic pressure pulses.
  3. 3 . A downhole hydraulic fracturing system for generating cyclic pressure pulses within a wellbore, the system comprising: a) a downhole pulsing tool positioned within the wellbore and mechanically coupled to a drill string above the downhole pulsing tool, the pulsing tool comprising an inner mandrel piston and fluid chamber, the piston moves to create high-pressure fluid waves by rapidly increasing pressure in the system; b) an injector tool positioned below the downhole pulsing tool, and in fluid communication therewith, the injector tool configured to receive the high-pressure fluid waves; c) wherein the injector tool comprises: a one-way check valve positioned at an inlet of the injector tool and configured to permit downward fluid flow while preventing reverse flow, and a closed distal end defining a confined fluid volume within the injector tool; d) wherein the confined fluid volume and geometric configuration of the injector tool cause reflection of the high-pressure fluid waves, resulting in one or more amplified pressure pulses within the injector tool; and e) wherein the amplified pressure pulses are transmitted from the injector tool into a surrounding formation.
  4. 4 . A method of hydraulically fracturing a subsurface formation using a downhole reservoir stimulation system, comprising of a) positioning a downhole pulsing tool within a wellbore, the downhole pulsing tool being capable of autonomous generation of cyclic pressure pulses independent of drill string tubular movements; b) activating the downhole pulsing tool to generate high-frequency pressure pulses; c) dynamically adjusting pulse pressure intensity, frequency, and amplitude from the surface in real-time, based upon formation response and downhole fluid pressure data captured by an integrated downhole pressure sensor; d) continuously monitoring pulse impact on the formation, including measurement of pressure decay trends and stimulated reservoir volume (SRV); e) controlling fluid injection through specialized injector tool nozzles, maintaining nozzle closure until a predefined differential pressure threshold is achieved, optimizing fluid pulse velocity, proppant transport efficiency, and fracture complexity; and f) transmitting collected downhole pressure data and analysis results to the surface for real-time or post-operation analysis.
  5. 5 . The method of claim 4 , wherein cyclic pressure pulses autonomously sustain themselves via a mechanical oscillatory feedback mechanism, employing stored mechanical energy from at least one of a spring-loaded assembly or a compressed gas chamber.
  6. 6 . The method of claim 4 , further comprising: remotely activating a specialized anchoring mechanism via at least one of an RFID tag recognition mechanism or a ball drop mechanism to securely position and anchor the downhole pulsing tool within a wellbore casing.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of, and claims benefit of, U.S. application Ser. No. 12/084,954, filed on Sep. 8, 2023, and assigned to the assignee of the present application. The entirety of U.S. application Ser. No. 12/084,954 is hereby incorporated by reference. BACKGROUND Field of the Invention Embodiments disclosed herein relate generally to apparatus and methods for creating and stimulating fractures within a subsurface formation using wellbore-deployed tools capable of generating pulse-based hydraulic fracturing. More specifically, the present disclosure pertains to a downhole reservoir stimulation tool operatively coupled to an injector tool, enabling a hybrid fracturing approach that integrates conventional hydraulic fracturing with downhole pulse hydraulic fracturing. This hybrid technique reduces surface energy demands, enhances fracture initiation, increases fracture density, and improves proppant distribution, thereby maximizing reservoir permeability and overall production efficiency. Unlike the system disclosed in U.S. application Ser. No. 12/084,954, this present disclosure includes: a mechanism that enables real-time, surface-controlled adjustment of pulse intensity; a downhole system capable of generating self-sustained pulsing independent of tubular movement, a downhole sensor system configured to detect, record, and analyze downhole fluid pressure and other critical parameters and additional embodiments that enhance energy transfer efficiency, increase fracture complexity, and optimize proppant transport. The present disclosure and the hybrid technique introduced can be applied to all areas where hydraulic fracturing is performed; such as, but not limited to, hydraulic fracturing of new wells, hydraulic fracturing of mature wells, hydraulic fracturing of geothermal well, hydraulic fracturing in carbon capture and storage operations, hydraulic fracturing in critical elements mining operations. Background Art Hydraulic fracturing, commonly referred to as “fracking,” has been widely utilized for decades to enhance hydrocarbon production from both conventional and unconventional reservoirs, as well as geothermal formations. The technique involves the high-pressure injection of fracturing fluid-typically composed of water, proppant, and chemical additives-into a wellbore to create fractures in the rock, thereby increasing formation permeability and improving fluid flow. Since its early development, hydraulic fracturing has evolved significantly. Traditional hydraulic fracturing methods primarily rely on a constant-flow, sustained-pressure injection approach, where fracturing fluid is continuously pumped at high pressure to propagate fractures. Advances in horizontal drilling and multi-stage fracturing have enabled access to low-permeability formations, such as shale, unlocking vast hydrocarbon reserves. However, research indicates that constant-flow hydraulic fracturing exhibits several fundamental inefficiencies compared to variable or pulse-based fracturing techniques. Despite its success in stimulating reservoirs, conventional hydraulic fracturing presents significant efficiency and operational limitations: Key challenges associated with conventional hydraulic fracturing include: Limited Energy Efficiency—Pressure transmission from the surface to the formation is inefficient due to frictional losses within the wellbore, reducing the overall energy available for fracture propagation. Restricted Fracture Complexity—Continuous high-pressure injection tends to produce predominantly planar fractures, limiting the development of secondary and tertiary fracture networks necessary for increased permeability. Inconsistent Proppant Transport—Proppant distribution within fractures is often uneven, as settling effects reduce fracture conductivity and long-term reservoir performance. High Environmental Impact—Conventional hydraulic fracturing operations require large volumes of water and chemical additives, produce toxic flowback fluids, and generate high CO2 emissions from diesel-powered pumping systems. Recent studies and field trials have demonstrated that variable-pressure pulse hydraulic fracturing—where fluid injection pressure is cyclically modulated or pulsed—offers significant advantages over the conventional constant-flow sustained-pressure approach. These findings highlight: More Effective Fracture Propagation—Pulse-based fracturing introduces cyclic stress variations, which enhance fracture complexity by promoting multiple branching fractures rather than uniform planar fractures. Improved Energy Transfer—Research shows that alternating pressure pulses improve stress redistribution, allowing more efficient energy delivery to the formation and minimizing frictional losses in the wellbore. Superior Proppant Transport—Controlled pressure pulses create fluid acceleration-deceleration cycles, keeping proppant suspended for longer durations and e