CN-121976781-A - Self-advancing jet drilling and instant gas fracturing integrated system and method

CN121976781ACN 121976781 ACN121976781 ACN 121976781ACN-121976781-A

Abstract

The application relates to the technical field of unconventional oil gas and geothermal resource development, in particular to a self-advancing jet drilling and instant gas fracturing integrated system and a method, wherein the system comprises a ground supply and control unit, a continuous pipe and a jet fracturing drill bit assembly connected with the tail end of the continuous pipe, the jet fracturing bit assembly comprises a high-pressure gas channel, an annular chamber, an axial nozzle and a radial nozzle, wherein the annular chamber is divided into a propping agent chamber and an instant pulse fracturing chamber by an annular sliding block. The method includes periodically cycling the steps of axial drilling, radial fracturing, and proppant injection. The application realizes the fusion of drilling and fracturing in time and space, converts drilling energy into fracturing energy in situ, forms an enhanced shaft wrapped by a continuous fracturing ring, and has the outstanding advantages of simplified working procedure, short working period, high energy utilization rate and continuous and uniform reservoir reconstruction.

Inventors

HOU PENG
LI LEQI
LIU QUANSHENG
WU ZHIJUN
ZHANG CHUANJIU

Assignees

武汉大学

Dates

Publication Date: 20260505
Application Date: 20260129

Claims (10)

1. The self-advancing jet drilling and immediate gas fracturing integrated system is characterized by comprising a continuous pipe and a jet fracturing drill bit assembly connected to the tail end of the continuous pipe; The continuous pipe comprises a first inner pipe and a first outer pipe which are coaxially sleeved, wherein a central channel is arranged in the first inner pipe and used for injecting high-pressure gas; The jet fracturing drill bit assembly comprises a second inner pipe and a second outer pipe which are coaxially sleeved, wherein a high-pressure gas channel communicated with a central channel is arranged in the second inner pipe, axial nozzles are arranged at the end part of the second inner pipe, and a plurality of radial nozzles are uniformly distributed on the periphery of the second outer pipe; And a switching valve is arranged in the second inner pipe and is used for guiding high-pressure gas in the high-pressure gas channel to the axial nozzle so as to realize axial drilling, or guiding the high-pressure gas to the instant pulse fracturing chamber through the communication hole and then spraying the high-pressure gas out of the radial nozzle so as to realize radial fracturing.
2. The integrated self-advancing jet drilling and instant gas fracturing system of claim 1, wherein the annular slide block is axially slidably arranged in the annular chamber, and when high-pressure gas in the high-pressure gas channel flows to the instant pulse fracturing chamber, the high-pressure gas can push the annular slide block to slide along the annular chamber, and a limiting assembly is arranged in the annular chamber and used for limiting the sliding stroke of the annular slide block.
3. The integrated self-advancing jet drilling and instant gas fracturing system of claim 2 wherein said spacing assembly comprises a plurality of telescoping members spaced along the length of said second inner tube, said telescoping members configured to extend/retract radially within said annular chamber.
4. The integrated system of self-advancing jet drilling and instant gas fracturing according to claim 1, wherein a high-pressure gas jet nozzle is rotatably arranged at the end part of the second inner tube, the axial nozzle is arranged on the high-pressure gas jet nozzle, and the high-pressure gas jet nozzle can rotate to adjust the jet angle of the axial gas jet.
5. The integrated system of self-advancing jet drilling and instant gas fracturing according to claim 1, wherein a connecting nipple and a near-bit measuring nipple are connected between the coiled tubing and the jet fracturing bit assembly, a first channel and a second channel are arranged in the connecting nipple and the near-bit measuring nipple in a penetrating mode, the first channel is used for communicating the central channel with a high-pressure gas channel, and the second channel is used for communicating the annular channel with a propping agent chamber.
6. The integrated self-advancing jet drilling and instant gas fracturing system of claim 1 further comprising a surface supply and control unit.
7. The integrated system of self-advancing jet drilling and instant gas fracturing according to claim 1, wherein the second outer pipe wall is embedded with a distributed temperature/acoustic wave sensing optical fiber cable.
8. A self-advancing jet drilling and immediate gas fracturing integrated method is characterized in that the method is implemented by adopting the self-advancing jet drilling and immediate gas fracturing integrated system as set forth in any one of claims 1-7, and comprises the following steps: The method comprises the following steps of axially drilling, namely lowering the jet fracturing drill bit assembly to the initial depth of a reservoir through a continuous pipe, injecting high-pressure gas into a central channel, opening a switching valve, and spraying the high-pressure gas from an axial nozzle through the high-pressure gas channel to realize axial drilling; radial fracturing, namely after axial drilling for a certain distance, closing or narrowing an axial nozzle, closing a switching valve, enabling high-pressure gas in a high-pressure gas channel to enter an instant pulse fracturing chamber through a communication hole, enabling the pressure in the instant pulse fracturing chamber to quickly rise to the opening pressure of the radial nozzle, opening the radial nozzle, enabling the high-pressure gas to act on a well wall in a pulse mode, and enabling surrounding rock fracturing to generate a radial multi-crack system; The propping agent is injected, namely, after the high-pressure gas pulse is ended, the propping agent is injected into the annular channel, and flows out of the radial nozzle through the propping agent chamber to prop up the crack formed in the radial fracturing step; The steps of axial drilling, radial fracturing and proppant injection are repeatedly carried out, and the process is circulated until the operation of the target interval is completed, and finally a drilling channel surrounded by continuous or overlapped fracturing fracture rings is formed.
9. The method of integrating self-advancing jet drilling and instant gas fracturing according to claim 8, wherein in the radial fracturing step, the peak value of the air pressure pulse of the radial nozzle is adjusted by adjusting the telescopic state of each telescopic piece on the second inner tube to limit the sliding stroke of the annular sliding block, so that the volume of the instant pulse fracturing chamber is adjusted.
10. The method of integrating self-advancing jet drilling and immediate gas fracturing according to claim 8, wherein in a cycle of axial drilling, radial fracturing and proppant injection, the stopping time of axial drilling is judged according to any one of the following judging criteria, wherein the drilling length reaches a preset value, near-bit acoustic wave sensing shows that the drilling enters a denser or natural fracture development section, or distributed acoustic wave sensing shows that Kong Zhouwei fracture events are active.

Description

Self-advancing jet drilling and instant gas fracturing integrated system and method Technical Field The application relates to the technical field of unconventional oil gas and geothermal resource development, in particular to a self-advancing jet drilling and instant gas fracturing integrated system and method. Background For development of low permeability reservoirs, a serial operation mode of drilling first, completing later and fracturing in a subdividing way is commonly adopted at present. In the mode, all drilling operations are finished first, a well bore is established, then a casing is put in, well cementation is carried out, and staged fracturing transformation is carried out through perforation or bridge plug packing and other modes. Although this model supports the exploitation of unconventional resources for a considerable period of time, its inherent process fracturing presents a number of systematic drawbacks that have gradually become bottlenecks that limit cost-reduction and efficiency-enhancement and scale-up. The existing serial operation mode mainly has the inherent defects of 1, procedure fracturing, long period and high cost, namely two stages of completely independent drilling (drilling) and reservoir modification (fracturing), different equipment, teams and operation time are needed, the period from drilling to production is long, the comprehensive cost is high, and 2, the well shaft integrity is damaged, namely, a formed open hole or casing well shaft is subjected to repeated high-pressure fluctuation in subsequent large fracturing construction, and well wall collapse, casing damage or cement ring sealing failure are easily caused. 3. The initiation point of the crack is limited, the transformation is insufficient, the crack can only be initiated from a preset perforation cluster or an open hole section, the transformation range is limited by the preset points, and continuous and uniform reservoir contact along the axial direction of the shaft is difficult to realize. 4. The energy utilization rate is low, the mechanical energy consumed in the drilling process (rock breaking of the drill bit) is not utilized, and a large amount of energy (hydraulic pressure or air pressure) is needed to be reinjected in the fracturing process, so that energy flows are broken, and no cooperation is formed. Although "well-fracturing" linkage concepts have been developed, such as attempts to inject fracturing fluid through the drill string after drilling, the operations are still sequential in nature, merely optimization of the operation joints, rather than innovation of the process principles, and the equipment does not achieve fundamental integrated integration, has limited synergistic potential, and often introduces additional operational complexity and risk. Disclosure of Invention In order to solve the problems of separation of drilling and fracturing procedures, low efficiency and high cost in the existing hypotonic reservoir development, the application provides a self-advancing jet drilling and instant gas fracturing integrated system and method. The application provides a self-advancing jet drilling and instant gas fracturing integrated system which adopts the following technical scheme: a self-advancing jet drilling and immediate gas fracturing integrated system comprises a continuous pipe and a jet fracturing drill bit assembly connected to the tail end of the continuous pipe; The continuous pipe comprises a first inner pipe and a first outer pipe which are coaxially sleeved, wherein a central channel is arranged in the first inner pipe and used for injecting high-pressure gas; The jet fracturing drill bit assembly comprises a second inner pipe and a second outer pipe which are coaxially sleeved, wherein a high-pressure gas channel communicated with a central channel is arranged in the second inner pipe, axial nozzles are arranged at the end part of the second inner pipe, and a plurality of radial nozzles are uniformly distributed on the periphery of the second outer pipe; And a switching valve is arranged in the second inner pipe and is used for guiding high-pressure gas in the high-pressure gas channel to the axial nozzle so as to realize axial drilling, or guiding the high-pressure gas to the instant pulse fracturing chamber through the communication hole and then spraying the high-pressure gas out of the radial nozzle so as to realize radial fracturing. Further, the annular sliding block is arranged in the annular chamber in an axial sliding manner, when high-pressure gas in the high-pressure gas channel flows to the instant pulse fracturing chamber, the high-pressure gas can push the annular sliding block to slide along the annular chamber, and a limiting assembly is arranged in the annular chamber and used for limiting the sliding stroke of the annular sliding block. Further, the spacing assembly includes a plurality of telescoping members spaced apart along the length of the second i