WO2017037746A2

WO2017037746A2 - The method of implementation of versa fracking of oil and gas wells

Info

Publication number: WO2017037746A2
Application number: PCT/IN2016/050293
Authority: WO
Inventors: Rajesh R. Nair; Manjunath G. LINGAREDDY; Thirumalachari SUNDARARAJAN; Anatolii O VASYLCHENKO
Original assignee: Indian Institute Of Technology Madras
Priority date: 2015-09-02
Filing date: 2016-09-02
Publication date: 2017-03-09
Also published as: WO2017037746A3

Abstract

The disclosure in various embodiments is related to a method of versa fracking for increasing oil and gas production rate in well completion stage and obtaining total recovery of oil and gas in later stages of production. The method exposes existing cracks in addition to forming new cracks in the reservoir through a sharp hydrodynamic link in the bottom hole and tubing space filled with air under atmospheric pressure or connected to atmosphere. The method involves running tubing filled with air under atmospheric pressure or connected to the atmosphere into the bottom hole of the well using cable, closing the lower end of the tubing and impacting versa fracking in the reservoir.

Description

THE METHOD OF IMPLEMENTATION OF VERSA FRACKING OF OIL AND GAS WELLS

TECHNICAL FIELD

[0001] The disclosure relates generally to oil and gas producing industry and in particular to a method of versa fracking for increasing oil and gas production rate in well completion stage and obtaining total recovery of oil and gas in later stages of production.

DESCRIPTION OF THE RELATED ART

[0002] The pay zone of wells that are ceased, cemented and perforated, as a rule are damaged with particles and fluids of muds and slurries. The most effective way to remove dirt from the holes of perforation, as well as from pores and cracks of bottom hole formation zone is through the effect of differential pressure drop. Oil and gas production in these wells are stimulated by sharp decline in pressure to enhance cleaning of mudding off and bridging pay zone for disclosure of existing cracks and formation of new. [0003] RU patent 2511220 to Vladimirovich discloses a method for formation wellbore zone treatment involving fluid pumping into the wellbore cavity having pressure oscillations generated by operating drain valves. Another patent RU2511321 discloses a method of multi-pulse source impacting on well walls filled with liquid. The system includes sealed chambers separated by valves and made of cylinders equipped with windows and differential pistons. However, these methods require the use of complex equipment in the well.

[0004] One other patent UA87016 discloses a method for development of hydrocarbon deposits that includes breaking balloons filled with air at atmospheric pressure when lowered in the well bottom. Balloons filled with air at atmospheric pressure provide a sharp decrease in well pressure, but the power bottom borehole implosion such as vacuum bomb was not high enough, thus making the method ineffective.

[0005] The present disclosure describes a method of versa fracking for enhanced oil and gas recovery through the use of decreased pressure. SUMMARY

[0006] The disclosure relates to a method of versa fracking for enhanced oil and gas recovery by providing a sharp decline in bottom hole pressure for ensuring cleaning of mudding off and bridging pay zone. The method exposes existing cracks in addition to forming new cracks in the reservoir through a sharp hydrodynamic link in the bottom hole and tubing space filled with air under atmospheric pressure or connected to atmosphere.

[0007] The method comprises the steps of: running tubing filled with air under atmospheric pressure or connected to the atmosphere into the bottom hole of the well using cable, closing the lower end of the tubing, impacting versa fracking to the reservoir, and pulling the tubing up to change the sealing for next cycle of versa fracking shock.

[0008] In one embodiment, the lower end of the tubing is closed with a black flange or diaphragm whose strength is equivalent to the hydrostatic pressure in the well plus 5 - 25 kg/cm . In another embodiment, the tubing is pulled from the well with the help of a metal wire rope or a cable logging or coiled tubing.

[0009] In one other embodiment, the method involves impacting versa fracking shock to the reservoir by perforating the black flange or diaphragm installed on the lower side of the tubing with the use of a shaped charge to provide a hydrodynamic link in the bottom hole.

[0010] In one other embodiment, a sharp hydrodynamic link in the bottom hole with tubing space filled with air under atmospheric pressure or connected to the atmosphere is provided by destroying the black flange or diaphragm installed on the lower side of the tubing with the use of increased pressure in the well in the range of 5 - 25 kg/cm .

BRIEF DESCRIPTION OF DRAWINGS

[0011] The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings, in which:

[0012] Fig. 1 illustrates the method of versa fracking.

[0013] Fig. 2 shows scheme of the equipment featuring a black flange in a deep well during versa fracking (1- reservoir; 2 - perforations; 3 - cement; 4 - production casing; 5 - compressor tubing; 6 - metal wire rope or cable logging; 7 - completion fluid; 8 - tubing for Versa Fracking; 9 - air under atmospheric pressure. 10 -black flange; 11 - shaped charge; 12 - direction of bridging plugging move; 13 - Packer). [0014] Fig. 3 shows scheme of the equipment featuring a diaphragm in a deep well during versa fracking (1- reservoir; 2 - holes of perforation; 3 - cement; 4 - production casing; 5 - compressor tubing; 6 - metal wire rope or cable logging; 7 - completion fluid; 8 - tubing for Versa Fracking; 9 - air under atmospheric pressure; 12 - direction of bridging plugging move; 14 - diaphragm; P - pressure in the well to crash the diaphragm to implement Versa Fracking shock).

[0015] Fig. 4 shows scheme of the equipment in a shallow well during versa fracking (1- reservoir; 2 - holes of perforation; 3 - cement; 4 - production casing; 5 - compressor tubing; 7 - completion fluid; 8 - tubing for Versa Fracking; 9 - air under atmospheric pressure. 10 - black flange; 11 - shaped charge; 12 - direction of bridging plugging move; 13-packer; 14 - coiled tubing).

[0016] Referring to the drawings, like numbers indicate like parts throughout the views.

DETAILED DESCRIPTION

[0017] While the invention has been disclosed with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from its scope. [0018] Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of "a", "an", and "the" include plural references. The meaning of "in" includes "in" and "on." Referring to the drawings, like numbers indicate like parts throughout the views. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein.

[0019] The invention in its various embodiments proposes a method of versa fracking for enhanced oil and gas recovery by providing a sharp decline in bottom hole pressure for ensuring cleaning of mudding off and bridging pay zone. The method comprises the steps of: impacting versa fracking in the bottom hole of a well reservoir, as shown in FIG. 1. Running tubing filled with air under pressure of 1 kg/cm or under atmospheric pressure or connected to the atmosphere into the bottom hole of the well using cable in step 101, closing the lower end of the tubing in step 102. In one embodiment, in step 102, the lower end of the tubing is closed with a black flange or diaphragm whose strength is equivalent to the hydrostatic pressure in the well plus 5 - 25 kg/cm .

[0020] In the following step 103, versa fracking shock is impacted to the reservoir by perforating the black flange or diaphragm installed on the lower side of the tubing with the use of a shaped charge to provide a hydrodynamic link in the bottom hole. In one other embodiment, in step 103, the black flange or diaphragm installed on the lower side of the tubing is destroyed with the use of increased pressure in the well in the range of 5 - 25 kg/cm . In the next step 104, the tubing is pulled up to change the sealing for the next cycle of versa fracking. In one embodiment, in step 104, the tubing is pulled from the well with the help of a metal wire rope or a cable logging or coiled tubing.

[0021] Examples

[0022] Example 1 [0023] FIG. 2 shows scheme of the equipment featuring a black flange in a deep well during versa fracking. The borehole exposed oil reservoir 1 in an interval of 3990-4000 m. The well was ceased by production column 4, perforated and operated for 10 years. Due to declining productivity of the well, intensification was done by versa fracking. The well was killed and a portable drilling rig was established. Then the tubing 8 (5 tubes connected together) which was filled with air 9 under atmospheric pressure was run in the bottom hole using the cable 6.

[0024] Versa fracking shock was then impacted to the reservoir by providing a sharp hydrodynamic link in the hole bottom with tubing space filled with air under atmospheric pressure by perforating the black flange 10 of run-flat tubing 8 using shaped charge 11. Then the tubing 8 was pulled up to change the black flange 10 and to fill the tubing space with air under atmospheric pressure for providing the next versa fracking shock. [0025] Examples 2

[0026] FIG. 3 shows scheme of the equipment featuring a diaphragm in a deep well during versa fracking. The borehole exposed oil reservoir 1 in an interval of 3990-4000 m. The well was ceased by production column 4, perforated and operated for 10 years. Due to declining productivity of the well, intensification was done by versa fracking. The well was killed and a portable drilling rig was established. Then the tubing 8 (5 tubes connected together) which was filled with air 9 under atmospheric pressure was run in the bottom hole using the cable 6.

[0027] The tubing 8 under atmospheric pressure had a diaphragm 13 on its lower end. The tube space of column 4 and 5 was closed on the well head, and pressure in the well was increased by means of a pump that caused the diaphragm 14 to crash and implements versa fracking shock. Then the tubing 8 was pulled up to change the black flange 10 and to fill the tubing space with air under atmospheric pressure for providing the next versa fracking shock. [0028] Example 3

[0029] FIG. 4 shows scheme of the equipment featuring a black flange in a shallow well during versa tracking. The borehole exposed oil reservoir 1 in an interval of 990-1000 m. The well was ceased by production column 4, perforated and operated for 10 years. Due to declining productivity of the well, intensification was done by versa fracking. The well was killed and a portable drilling rig was established. Then the tubing 8 (2 tubes connected together) which was filled with air 9 under atmospheric pressure was run in the bottom hole using the cable 6. [0030] Versa fracking shock was then impacted to the reservoir by providing a sharp hydrodynamic link in the bottom hole with tubing space filled with air under atmospheric pressure by perforating the black flange 10 of run-flat tubing 8 using shaped charge 11. Then the tubing 8 was pulled up to change the black flange 10 and provide the next versa fracking shock. [0031] The above described method of versa fracking enhances oil and gas recovery by power comparable to the impact of hydraulic fracturing. The method does not require the use of external energy source but depends wholly on the differential pressure between atmospheric pressure and formation fluid pressure. Versa fracking technology is significantly cheaper than the usual hydraulic fracturing and does not pollute the environment.

Claims

I/We claim:

1. A method of the Versa Fracking for enhance oil and gas recovery which provides the use of formation energy to ensure cleaning of mudding off and bridging pay zone, disclosure of existing cracks and formation high permeable collector due to sharp decline in pressure in borehole bottom.

2. A method of the Versa Fracking according to claim 1 provides sharp decline in bottom borehole pressure due to directly and sharp linkage with atmosphere or with a system of tubing which space is filled with air under pressure 1 kg/cm .

3. A method of the Versa Fracking according to claim 1 provides the running into bottom hole the tubing which space filled the air under atmospheric pressure or connected with atmosphere and which lower end of this tubing is closed with diaphragm which strength is equivalent to the hydrostatic pressure in the well plus 5-25 kg/cm to provide opportunity the diaphragm destruction due to increasing the pressure in the well by an amount 5-25 kg/cm .

4. A method of the Versa Fracking according to claim 1 provides the sharp hydrodynamic linkage the bottom borehole with tubing space filled the air under atmospheric pressure or connected with atmosphere due to perforation the black flange that is installed on the lower end of the tubing with the use a shaped charge.

5. A method of the Versa Fracking according to claim 1 wherein the running of the tubing filled the air under atmospheric pressure or connected with atmosphere into bottom borehole, providing the Versa Fracking technology and the use the tubing for oil or gas recovery.

6. A method of the Versa Fracking according to claim 1 wherein the running of the tubing filled the air under atmospheric pressure or connected with atmosphere into bottom borehole, providing the Versa Fracking technology and the pulling this tubing from the well provides with the help of metal wire rope or cable logging or coiled tubing.