CN106437633A - Shale gas mining device and method with combination of lasers and water jet technologies - Google Patents

Abstract

The invention discloses a device and method for exploiting shale gas combining laser and water jet technologies. The device mainly includes a laser head, a water jet gun head and the like. The laser head emits a controllable energy laser, the water jet gun head shoots the active liquid, the water jet gun head shoots the active liquid to the rock surface, and uses the laser to heat the active liquid to generate a local heating and thermal reaction liquid, which produces an explosive chemical reaction in the liquid , to generate high pressure to crush the rock, making the shale particles smaller and releasing more shale gas. In order to achieve the purpose of quickly breaking shale and efficiently obtaining shale gas. This method can replace the currently used method of hydraulic fracturing to break rocks, the work efficiency can be greatly improved, and the efficient exploitation of shale gas can be realized. The active liquid used does not contain chemical enhancers and other polluting reagents, and will not cause environmental problems such as water pollution, chemical pollution, and methane pollution.

Description

A device and method for exploiting shale gas combining laser and water jet technology

technical field

The invention belongs to the technical field of shale gas exploitation, and relates to a shale gas exploitation device and method, in particular to a shale gas exploitation device and method utilizing a combination of laser and water jet technology.

Background technique

With the increasing shortage of oil and gas resources and the consideration of energy security, shale gas, an unconventional natural gas resource that can effectively relieve the world's energy pressure, is being sought after by countries all over the world, and has become one of the hot spots in world energy research. Its development And utilization is getting more and more attention from all over the world. Shale gas is a valuable resource, high-quality energy and chemical raw material, and can be used as a replacement or supplementary energy source for conventional natural gas. The world's shale gas resources are abundant, but they have not been extensively explored and developed. The fundamental reason is that the permeability of shale matrix is very low (generally less than 1mD), and the exploration and development technical requirements are high and difficult.

Shale gas is natural gas that occurs in dark muddy shale layers or high-carbon muddy shale layers. It can be generated in various stages of organic origin. Part of the natural gas exists in the free phase state (about 50%) in shale layer fractures, Shale layer pores and other storage spaces, the other part exists in the state of adsorption (about 50%) on the surface of kerogen, clay particles and clay pores.

The development of shale gas in the world is still in the early stage. The United States has built a large-scale shale gas production capacity. Generally buried deep, further increasing the difficulty of development.

Existing shale gas mining mainly relies on its own desorption. After a period of gas production, the output of shale gas drops sharply, and the effect of shale gas extraction is not ideal. The output is low and unstable, and cannot meet the industrial development standards. The main reasons for the low gas production in shale gas exploitation are: compared with conventional natural gas, the storage method of shale gas is mainly adsorption, the reservoir energy is low (low pressure), and the permeability is poor. The production process of shale gas is first desorb and then percolate in the porous medium. It is difficult to obtain high gas production and recovery only relying on self-desorption, and new methods to increase production speed (or daily gas production) and recovery must be found and studied.

In order to improve the recovery rate of shale gas, production stimulation measures can be taken when the shale gas production is lower than the industrial development standard (1000 cubic meters per day for a single well). Existing stimulation measures mainly use hydraulic fracturing for reservoir stimulation. Hydraulic fracturing technology, including clear water fracturing technology, multi-stage fracturing technology, simultaneous fracturing technology, repeated fracturing technology, etc., is currently the only golden key that can open shale gas deposits, which has led to a rapid increase in shale gas production . It primarily uses gritty water with sand as the proppant, in addition to 2% or less chemical reinforcement. The principle is to pump the fracturing fluid into the bottom of the well through the surface pump truck. When the high-pressure fluid is injected into the well and cracks the rock formation, the proppant in the high-pressure fluid can hold the fracture and make it a high-speed permeation channel for oil and gas directional drilling. . On the one hand, improper purification of circulating fracturing fluid may cause serious environmental problems, because hydraulic fracturing technology is used in industry, and as we all know, it will use a lot of water and cause water pollution problems, chemical pollution, methane pollution, etc. On the other hand, although this method increases the seepage channel to allow part of the desorbed shale gas to flow out, it does not fundamentally accelerate the desorption of adsorbed shale gas, and the effect of increasing production is limited. At the same time, most shale gas is buried deep, and hydraulic fracturing needs to provide sufficient pressure. It leads to large equipment investment and high operating costs, which limits its wide application.

In addition, there is another method for increasing production of shale gas: CO ₂ adsorption method, which uses CO ₂ to have a higher adsorption capacity than methane (CH ₄ ), injecting CO ₂ into shale formations, pushing out methane or changing its adsorption characteristics . This method must also be properly depressurized. During the depressurization process, _CH4 desorbs, and _CO2 has strong adsorption and occupies the position of _CH4 , so that _CH4 remains in a free state. The specific process is: the production well opens the shale gas well to reduce the pressure, the injection well injects CO ₂ , after the pressure is reduced, the CH ₄ is desorbed into a free state, and the CO ₂ is adsorbed. Then the injection pressure is increased, and CH ₄ flows along the pores of the shale formation to be produced from the gas well. After a period of production according to the above method, the pressure is lowered again, and the injection and output of the next cycle are performed. However, since the depressurization process takes place in the production well, while CO ₂ is injected in the injection well, the competition between CH ₄ and CO ₂ may not occur at the same time. In addition, the effective cycle of shale gas production is shortened due to the repeated cycle of pressure boost and depressurization. Therefore, the daily gas production cannot be greatly increased. Moreover, this production increasing method has complex equipment and extremely high preparation costs, which also make it only stay in the laboratory research stage.

Contents of the invention

The purpose of the present invention is to provide a new method for mining shale gas by combining laser and water jet technology, give full play to the advantages of laser technology and water jet technology, and solve the problem of low efficiency of mining shale gas and the process of mining shale gas. The problem of low mining depth caused by environmental pollution and insufficient energy at the bottom of the well has realized the efficient and clean production of shale gas and guaranteed the national energy strategic security.

The technical solution adopted by the device of the present invention is: a shale gas mining device combining laser and water jet technology, characterized in that it includes energy optical brazing, side-by-side connection buckles, water jet gun head, laser head holder, Laser head, water jet gun head holder;

The energy optical fiber is connected with the laser head, and the laser energy is transmitted to the laser head by the energy optical fiber, and the laser head is used as the output port of the laser beam; the laser head holder is installed between the energy optical fiber and the laser head;

The water jet gun head holder is installed on the water jet gun head for injecting active liquid;

The water jet gun head holder and the laser head holder are connected side by side by side-by-side connecting buckles, so as to realize the coordinated and orderly operation of water jet and laser.

Preferably, a searchlight, a gas sensor, a temperature sensor and a miniature camera are arranged on the holder of the water jet gun head.

The technical solution adopted by the method of the present invention is: a method for exploiting shale gas combining laser and water jet technology, characterized in that: the active liquid is injected from the water jet gun head so that the active liquid covers the shale layer; The laser produces a controllable high-energy laser, which is transmitted to the laser head through the energy optical fiber. After being focused by the laser head, the laser beam acts on the active liquid, causing the active liquid to generate local heating and thermal reaction liquid, and an explosive chemical reaction occurs in the liquid. High pressure is used to crush rocks, the crushed rock particles are finer, the rock breaking speed is faster, and the amount of shale gas released is larger; at the same time, high-speed active liquid is used to remove the broken rocks, achieving high-speed rock breaking, and greatly improving the shale gas output. mining efficiency.

Preferably, the active liquid is a neutral active liquid, has no pollution to the environment, and is a clean liquid.

Preferably, the laser is a femtosecond laser, picosecond laser or nanosecond laser, and the energy output is controllable.

The water jet gun head of the present invention is equipped with highly sensitive gas sensors, temperature sensors, miniature cameras, searchlights, etc.; the reason why it is installed on the water jet gun head instead of the laser head holder is that the laser head holder The temperature of the laser is high during operation, and the normal operation of gas sensors, temperature sensors, micro cameras, searchlights, etc. cannot be guaranteed.

The gas sensor installed on the water jet gun head of the present invention is used to sense the strength of shale gas in rocks, so as to find places with high shale gas concentration to carry out laser water jet breaking rocks to get gas; The installed temperature sensor is used to detect the temperature of the rock-breaking area. This temperature is set as the optimum temperature for shale gas flow. When the temperature is too high, the output power of the laser beam is reduced to lower the temperature; when the temperature is low, the laser beam is enhanced The laser power increases the temperature and keeps the temperature in the rock-breaking area; the micro-camera installed on the head of the water jet gun is used to observe the situation in real time during the process of mining shale gas by laser water jet blasting; the searchlight installed on the head of the water jet gun It is used to provide a certain light source so that the micro camera can clearly see the real-time situation in the process of laser water jet rock breaking.

With the successful development of femtosecond laser, picosecond laser and nanosecond laser and the continuous maturity of technology, the reliability and stability can be well guaranteed, the controllability is further enhanced, and the cost performance is greatly improved. At the same time, with the development of Micro-Electro-Mechanical System (MEMS, Micro-Electro-Mechanical System) technology, the volume of lasers can be continuously miniaturized, which has the potential to promote the application of lasers in the exploitation of shale gas.

The present invention proposes a new method of mining shale gas by combining laser and water jet technology. The two methods complement each other in advantages. The active liquid is activated by the laser, and an explosive chemical reaction is generated in the liquid to achieve rapid and large-scale shale breaking. The purpose is to greatly improve the extraction efficiency of shale gas.

Description of drawings

Fig. 1 is a schematic diagram of the device of the embodiment of the present invention.

detailed description

In order to facilitate those of ordinary skill in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit this invention.

Please refer to Fig. 1, a shale gas exploitation device combining laser and water jet technology provided by the present invention, including energy optical brazing 1, side-by-side connection buckle 2, water jet gun head 4, laser head holder 5, laser head 6. Searchlight 7, gas sensor 8, active liquid 9, temperature sensor 10, micro camera 11, laser beam 12, water jet nozzle holder 13. The energy optical fiber 1 is connected with the laser head 6 , and the laser head holder 5 is installed between the energy optical fiber 1 and the laser head 6 . The laser energy is transmitted from the energy optical fiber 1 to the laser head 6 , and the laser head 6 serves as the output port of the laser beam 12 . Searchlight 7, gas sensor 8, temperature sensor 10 and miniature camera 11 are installed on the water jet gun head holder 13; The jet and laser operate synergistically. The gas sensor 8 is used to detect the concentration of shale gas released in the shale 3, so as to find places with high shale gas concentration and carry out local blasting of laser water jet to obtain gas, which greatly improves the accuracy and efficiency of mining shale gas; The temperature sensor 10 is used to monitor the temperature of the broken shale 3 area, and the temperature is set to the optimum temperature for shale gas flow. When the temperature is too high, the output of the laser beam 12 is stopped; when the temperature is low, the output of the laser beam 12 is enhanced. power to keep the temperature in the rock-breaking area stable; the micro-camera 11 is used for real-time observation of the situation in the shale gas mining process by laser water jet blasting for real-time control; the searchlight 7 is used to provide a light source so that the micro-camera 11 can clearly observe the laser The situation in the process of water jet blasting to extract shale gas.

The water jet gun head 4 shoots the active liquid 9, so that the active liquid 9 covers the surface of the shale 3; the laser generates controllable high-energy laser, which is transmitted to the laser head 6 through the energy optical fiber 1, and the high-energy laser is focused by the laser head 6 and acts on the On the active liquid 9, make the active liquid generate local heating and heat reaction liquid, produce explosive chemical reaction in the liquid, generate high pressure to crush the shale 3, make the shale 3 become fine gravel, and release the contained in it For shale gas, the high-speed active liquid 9 ejected from the water jet gun head 4 removes the shale gravel broken by the pressure generated by the explosion, so as to realize high-speed rock breaking and high-efficiency gas recovery. After the temperature sensor 10 detects, the water jet gun head 4 sprays the active liquid 9, and the laser head 6 focuses on the active liquid 9, the shale 3 explodes, and obtains shale gas. The above steps are repeated to exploit shale gas. The reason why the method used in the present invention does not directly use the thermal effect of the laser to heat the rock 3 and thermally destroy the rock 3 is that the thermal damage to the shale may be accompanied by the chemical reaction of the shale gas in the shale 3. Changes and physical changes, which will greatly reduce the efficiency of shale gas extraction. The shale 3 broken by the pressure generated by the explosion is removed by using the high-speed active liquid 9 to realize high-speed blasting of the shale 3 and greatly improve the efficiency of shale gas exploitation.

The invention solves the problems of low shale gas exploitation efficiency, low exploitation depth caused by insufficient well bottom energy, environmental pollution caused by traditional exploitation of shale gas, and the like. There is no need for the action of high-pressure fluids, nor for fluids doped with chemicals.

It should be understood that the parts not described in detail in this specification belong to the prior art.

It should be understood that the above-mentioned descriptions for the preferred embodiments are relatively detailed, and should not therefore be considered as limiting the scope of the patent protection of the present invention. Within the scope of protection, replacements or modifications can also be made, all of which fall within the protection scope of the present invention, and the scope of protection of the present invention should be based on the appended claims.

Claims (5)

1. the exploitation shale device of air that a kind of laser and water-jet technology combine, it is characterised in that：Including energy light pricker（1）、 Junction button side by side（2）, water jet pipette tips（4）, laser head retainer（5）, laser head（6）, water jet pipette tips retainer（13）；

The energy light pricker（1）With laser head（6）It is connected, by energy light pricker（1）Transmission laser energy is to laser head（6）, swash Shaven head（6）As laser beam（12）Delivery outlet；The laser head retainer（5）Installed in energy light pricker（1）And laser head（6） Between；

The water jet pipette tips retainer（13）Installed in the water jet pipette tips（4）On, for projecting active liquid（9）；

The water jet pipette tips retainer（13）With laser head retainer（5）By junction button side by side（2）Link together side by side, Realize water jet and laser collaboration ordered operation.

2. the exploitation shale device of air that laser according to claim 1 and water-jet technology combine, it is characterised in that：Institute State water jet pipette tips retainer（13）On be provided with searchlight（7）, gas sensor（8）, temperature sensor（10）And it is miniature Photographic head（11）.

3. the exploitation shale gas method that a kind of laser and water-jet technology combine, it is characterised in that：By water jet pipette tips（4）Penetrate Go out active liquid（9）, make active liquid（9）Cover in shale（3）On；Controlled superlaser is produced by laser instrument, through energy Light pricker（1）Transmit to laser head（6）, through laser head（6）Laser beam after focusing（12）Act on active liquid（9）On, make activity Liquid（9）Local heating and thermal response liquid is produced, produces explosive chemical reaction in a liquid, produce high pressure and carry out cataclasite Stone, the rock particles crushed by which is thinner, and broken rock speed is fast, and the amount for discharging shale gas is bigger；While using high rate activated liquid（9） Fractured rock is removed, high speed broken rock is realized, shale gas exploitation efficiency is substantially improved.

4. the exploitation shale gas method that laser according to claim 2 and water-jet technology combine, it is characterised in that：Institute Active liquid is stated for neutral active liquid, environmentally safe, belong to clean type liquid.

5. the exploitation shale gas method that laser according to claim 2 and water-jet technology combine, it is characterised in that：Institute Laser instrument is stated using femto-second laser, picosecond laser or nanosecond laser, and energy output is controlled.