CN103867166A

CN103867166A - Device and method for supercritical carbon dioxide high-pressure jet flow plug removal seepage enhancement

Info

Publication number: CN103867166A
Application number: CN201410128288.0A
Authority: CN
Inventors: 倪红坚; 李木坤; 王瑞和; 霍洪俊
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2014-04-01
Filing date: 2014-04-01
Publication date: 2014-06-18
Anticipated expiration: 2034-04-01
Also published as: CN103867166B

Abstract

The invention belongs to the technical field of oil-gas well yield increase equipment and relates to a device and method for supercritical carbon dioxide high-pressure jet flow plug removal seepage enhancement. An oil pipe is sleeved with a casing pipe, a packer is arranged between the casing pipe and the oil pipe, and an exploder is arranged in the oil pipe and connected with the oil pipe; a piston is arranged below the exploder and the portion between the piston and the exploder is filled with propellant; a cylinder sleeve is arranged at the lower end of the piston and the piston moves downwards in the cylinder sleeve; a flow guide connector is arranged on the lower portion of the cylinder sleeve; a nozzle is arranged on the flow guide connector and a rupture disk or an elastic body is arranged on the outlet portion of the nozzle; after the propellant is ignited by the exploder, energy is generated, so that the piston is pushed to compress supercritical carbon dioxide, short-time supercritical carbon dioxide jet flow waves generated through breakage of the rupture disk or popup of the elastic body enable rock to crack initially, and cracks are expanded through the pressure of short-time supercritical carbon dioxide jet flow with the low viscosity of the supercritical carbon dioxide. According to the device and method for supercritical carbon dioxide high-pressure jet flow plug removal seepage enhancement, the structure is simple, operation is convenient, raw materials are easy to obtain, cost is low, the energy use rate is high, and the device and method are environmentally friendly.

Description

A kind of supercritical CO 2 high pressure jet de-plugging anatonosis device and method

Technical field:

The invention belongs to well production increment equipment technical field, relate to a kind of equipment and technique, particularly a kind of supercritical CO 2 high pressure jet de-plugging anatonosis device and method that realizes the de-plugging of Oil/gas Well near wellbore formation, anatonosis in once constructing.

Background technology:

In oil-gas mining, Oil/gas Well near wellbore formation fluid course is very easily stopped up, earial drainage area is little, near wellbore formation permeability becomes a key factor that affects the rate of oil and gas recovery, particularly for the old Oil/gas Well that is subject to various organic depositions and inorganic scale obstruction after being subject to the Oil/gas Well of mud contamination after completion and exploiting for a long time, its near wellbore formation permeability is low, cause the rate of oil and gas recovery to decline, at present, conventionally adopt waterpower acid fracturing to make seam anatonosis, but fracturing cost is high, little millions of, at most several ten million, and the compact sandstone gas to water-sensitive formation and shale gas well, anatonosis effect is also not obvious, if adopt non-aqueous fracturing fluid, such as the carbon dioxide of liquid state or foam, although the anatonosis effect having had, but device therefor complexity, raw material costliness, cost is high, in addition, adopt above-mentioned pressure break mode, high and the fragile oil pipe of hard formation initial cracking pressure and sleeve pipe, be not suitable for the mountain area that large truck enters, desert and swampy area.For above-mentioned shortcoming, there is high enegry gas fracturing and synergistic perforating technology that cost is relatively low, but do not applied so far, high energy gas hypertonia easy damaged sleeve pipe, the too low fracturing stratum that is difficult for; The burning of propellant is subject to temperature, pressure influence, pressure is difficult to prediction, and also someone proposes strong reductant to bring stratum into by jet, produces acetylene or hydrogen, and then be pressed into air produce blast come fracturing stratum, the method exist three problems: the one, strong reductant somewhat expensive; The 2nd, affected by stratum water content, the reaction speed of acetylene or hydrogen is difficult to control, and the air being pressed into easily easily carries acetylene or hydrogen toward depths, stratum reaching before explosion limit, can not produce blast crack initiation effect; The 3rd, to the extremely low stratum of moisture content and gas-bearing formation, such as dunn bass gas reservoir, the method is not only difficult to realize, and the air being pressed into easily reacts with natural gas, causes the well accident of exploding.

Summary of the invention:

The object of the invention is to overcome the shortcoming that prior art exists, seek design a kind of supercritical CO 2 high pressure jet de-plugging anatonosis device and method is provided, this apparatus structure is simple, and cost is low, and method is easy to realize, and can effectively increase near wellbore formation permeability.

The agent structure of the supercritical CO 2 high pressure jet de-plugging anatonosis device the present invention relates to achieve these goals, comprises oil pipe, sleeve pipe, packer, initiator, propellant, piston, cylinder sleeve, flow guiding connector and nozzle; Casing pipe sleeve forms upper lower channel built in the outside of oil pipe, in the upper lower channel between sleeve pipe and oil pipe, is evenly provided with packer, and the number of packer is set according to actual needs; Initiator is arranged in oil pipe, and is connected with oil pipe, and initiator adopts commercially available wireless or wired initiator; Initiator below is provided with piston, in the cavity forming, is filled with propellant between piston and initiator; Piston lower end is shaped with the cylinder sleeve that is full of supercritical carbon dioxide, and piston moves downward in cylinder sleeve; Cylinder sleeve bottom is provided with flow guiding connector, and flow guiding connector is shunted and leads the supercritical carbon dioxide in cylinder sleeve; In the middle of flow guiding connector, be uniformly distributed from top to bottom and be shaped with 1～10 nozzle, the exit of nozzle is shaped with rupture disk or elastic body.

The concrete steps that the present invention realizes supercritical CO 2 high pressure jet de-plugging anatonosis are:

(1), initiator ignites propellant, the energy that propellant combustion produces promotes the supercritical carbon dioxide in piston compression cylinder sleeve, the compression energy that the power conversion that propellant combustion is produced is carbon dioxide, realizes the gathering of energy;

(2), in the time that in cylinder sleeve, supercritical carbon dioxide pressure reaches 10～200MPa, the rupture disk fragmentation of nozzle exit or elastic body eject and form short time supercritical carbon dioxide jet, the shock wave of short time supercritical carbon dioxide jet makes rock in millisecond, produce incipient crack, and the low viscosity of supercritical carbon dioxide makes short time supercritical carbon dioxide jet pressure bamboo telegraph and vee crack in crack;

(3), after short time supercritical carbon dioxide jet jet finishes, packer maintains the high fluid pressure of 3～48 hours, make low viscous supercritical carbon dioxide in stratum, continue infiltrate and retain, and the formation fracture of expansion after short time supercritical carbon dioxide jet sprays, produce physical chemistry de-plugging, anatonosis effect;

(4), after removing seal for packer, strata pressure is higher than Oil/gas Well wellbore pressure, high-density CO 2 can backflow from stratum, carries out organic obstruction material and the inorganic obstruction material of near wellbore formation carbon dioxide solubility.

Operating principle of the present invention is: the one, under the deep-well of carbon dioxide more than 1000m, exist with supercriticality, and there is very high compressibilty, its density is 200-1200kg/m3, can store a large amount of elasticity energy, forms short time jet; The 2nd, water jet surge is static pressure 70%, and supercritical carbon dioxide jet rock breaking efficiency is 3.3 times of water jet, and therefore supercritical carbon dioxide jet has lower initial cracking pressure, can produce equal extent crack; The 3rd, supercritical carbon dioxide has the density near with water, can produce the impact force larger than other gas, and simultaneously supercritical carbon dioxide has the viscosity close with gas, and jet pressure can bamboo telegraph in hole and crack; The 4th, supercritical carbon dioxide can extract moisture in the clay of stratum and make clay shrink, increase degree of porosity, surface tension is low, easily with organic macromolecule is miscible and softening, decompose organic deposition, can be under water exists react generation solubility carbonic acid hydrogen salt with the inorganic scale such as insoluble carbonate.

The present invention compared with prior art, it is simple in structure, easy to operate, and raw material is easy to get, cost is low, capacity usage ratio is high, and environmental friendliness completes perforation, pressure break and carbon dioxide scale removal row dirt simultaneously, all can use in the area such as remote mountain areas, desert, both realized well production increment anatonosis, realized again energy-saving and emission-reduction, and avoided hypertonia and damage sleeve pipe.

Brief description of the drawings:

Fig. 1 is the agent structure schematic diagram of the supercritical CO 2 high pressure jet de-plugging anatonosis device that the present invention relates to.

Detailed description of the invention:

Also be described further by reference to the accompanying drawings below by embodiment.

Embodiment:

The agent structure of the supercritical CO 2 high pressure jet de-plugging anatonosis device that the present embodiment relates to comprises oil pipe 1, sleeve pipe 2, packer 3, initiator 4, propellant 5, piston 6, cylinder sleeve 7, flow guiding connector 8 and nozzle 9; Sleeve pipe 2 overlaps built in the outside of oil pipe 1 and forms upper lower channel, in the upper lower channel between sleeve pipe 2 and oil pipe 1, is evenly provided with packer 3, and the number of packer 3 is set according to actual needs; Initiator 4 is arranged in oil pipe 1, and is connected with oil pipe 1, and initiator 4 adopts commercially available wireless or wired initiator; Initiator 4 belows are provided with piston 6, in the cavity forming, are filled with propellant 5 between piston 6 and initiator 4; Piston 6 lower ends are shaped with the cylinder sleeve 7 that is full of supercritical carbon dioxide, and piston 6 moves downward in cylinder sleeve 7; Cylinder sleeve 7 bottoms are provided with flow guiding connector 8, and flow guiding connector 8 is shunted and leads the supercritical carbon dioxide in cylinder sleeve 7; In the middle of flow guiding connector 8, be uniformly distributed from top to bottom and be shaped with 1～10 nozzle 9, the exit of nozzle 9 is shaped with rupture disk or elastic body.

The concrete steps that the present embodiment is realized supercritical CO 2 high pressure jet de-plugging anatonosis are:

(1), initiator 4 ignites propellant 5, the energy that propellant 5 burnings produce promotes piston 6 and compresses the supercritical carbon dioxide in cylinder sleeve 7, by propellant 5 compression energy that the power conversion that produces is carbon dioxide that burns, realizes the gathering of energy;

(2), in the time that the interior supercritical carbon dioxide pressure of cylinder sleeve 7 reaches 10～200MPa, the rupture disk fragmentation in nozzle 9 exits or elastic body eject and form short time supercritical carbon dioxide jet, the shock wave of short time supercritical carbon dioxide jet makes rock in millisecond, produce incipient crack, and the low viscosity of supercritical carbon dioxide makes short time supercritical carbon dioxide jet pressure bamboo telegraph and vee crack in crack;

(3), after short time supercritical carbon dioxide jet jet finishes, packer 3 maintains the high fluid pressure of 3～48 hours, make low viscous supercritical carbon dioxide in stratum, continue infiltrate and retain, the formation fracture of expansion after short time supercritical carbon dioxide jet sprays, and produce physical chemistry de-plugging, anatonosis effect;

(4), packer 3 solutions are honored as a queen, strata pressure is higher than Oil/gas Well wellbore pressure, high-density CO 2 can backflow from stratum, carries out organic obstruction material and the inorganic obstruction material of near wellbore formation carbon dioxide solubility.

Claims

1. A supercritical carbon dioxide high-pressure jet flow deblocking and permeation increasing device is characterized in that the main structure includes oil pipes, casing pipes, packers, detonators, propellants, pistons, cylinder liners, diversion joints and nozzles; The upper and lower passages are formed on the outside of the tubing, and packers are evenly arranged in the upper and lower passages between the casing and the tubing, and the number of packers is set according to actual needs; the detonator is arranged in the tubing and connected to the tubing, The detonator adopts a commercially available wireless or wired detonator; a piston is arranged under the detonator, and the cavity formed between the piston and detonator is filled with propellant; The casing moves downward; the lower part of the cylinder liner is provided with a diversion joint, which diverts and guides the supercritical carbon dioxide in the cylinder liner; the middle of the diversion joint is evenly distributed from top to bottom with 1 to 10 nozzles. The outlet is made with a burst disc or elastic body.

2. a method adopting device as claimed in claim 1 to realize supercritical carbon dioxide high-pressure jet deblocking and increasing seepage, is characterized in that concrete steps are:

(1) The detonator ignites the propellant, and the energy generated by the propellant combustion pushes the piston to compress the supercritical carbon dioxide in the cylinder liner, and converts the energy generated by the propellant combustion into the compression energy of carbon dioxide to realize energy accumulation;

(2) When the supercritical carbon dioxide pressure in the cylinder liner reaches 10-200MPa, the bursting disc at the outlet of the nozzle is broken or the elastic body pops up to form a short-term supercritical carbon dioxide jet. The initial cracks are generated, and the low viscosity of supercritical carbon dioxide makes the short-term supercritical carbon dioxide jet pressure spread rapidly in the cracks to expand the cracks;

(3) After the short-time supercritical carbon dioxide jet flow ends, the packer maintains a high fluid pressure for 3 to 48 hours, so that the low-viscosity supercritical carbon dioxide continues to infiltrate and remain in the formation, and expands the short-time supercritical carbon dioxide Formation fractures after jet spraying produce physical and chemical blockage removal and permeability enhancement;

(4) After the packer is released, the formation pressure is higher than the wellbore pressure of the oil and gas well, and the high-density carbon dioxide can flow back from the formation, carrying out the organic and inorganic plugging substances dissolved by carbon dioxide in the formation near the wellbore.