LT3749B - Method for providing of user with a gas suplly - Google Patents

Abstract

The gas user supply method includes the formation of capacity-storage facilities above the exploited watery gas saturated horizon and the filling by the gas, when periodical action is being directed to the horizon and afterwards the gas is being collected for the users. The influence is brought by the resilient fluctuations making pressure differences, rising temperature, enacting electromagnetic wavering or by a combination of the above mentioned items. The efficiency of the method is highly improved when it is being used in seismically active regions or regions where resilient fluctuations take place.

Description

The invention relates to a method of supplying consumers with gas. Specifically, by supplying gas to consumers in the form of tanks, sampling and selection of the aquifers, drawn in and out of the immediate vicinity of the user, filled and filled with gas.

The invention may be utilized in the preparation of ready-to-use gas fields and the delivery of gas to the user in a simple and secure manner.

State of the art

Gas extraction is known to occur from gaseous, gas condensate, and oil-gas condensation sites that occur at sites of their natural formation that have occurred over a long geological period. Consumers' gas supply (industrial, municipal, etc.) is usually carried out according to the following scheme: Site treatment - Industrial gas preparation - Transport to gas consuming areas, where tanks are prepared, filled with gas and selected from consumers. Earlier technical solutions to this issue often (and still do) use the method of using underground tanks for gas storage close to the place of consumption. For example, such a method is described in F. A. Trebin, J. F. Makogon, K. S. Bosnijev Obtaining Natural Gas, Nedra Publishing Company, Moscow, 1976, 386 pages. Underground capacitance-bellifiers formed under the conditions of natural geological processes were used for the exploration process of already formed natural gas fields, determining their reserves according to the pressure drop of the bed. For example, according to 1983, July 30th USSR Copyright Certificate no. No. 1032171, the hopper located above the gas field, was used to estimate the inventory of the bed pressure drop by passing gas into it without further selection.

1974 November 21 USSR Copyright Certificate no. No. 442287 proposes to extract free gas from hydrated layers of gas by exposure to electromagnetic radiation oscillations or magnetostrictive borehole. It is known to operate oil wells by injecting a source of acoustic oscillations into the well, which causes gasification of the fluid column and facilitates gas lift mode operation. It is described in 1981. October 5 published in USSR Copyright Certificate no. 859606.

A method of producing gas is also known, whereby it is transported to the surface together with the bed fluid and subsequently separated from the liquid (Handbook of Petroleum Production, Nedra, Moscow, 1974, pp. 511-512).

1974 August 9 U.S. Pat. 4,040,487 and 1978. September 26 U.S. Pat. 4.116.276 describes a method for increasing the extraction of natural gas from an aqueous horizon (containing water and gas) by employing a method of pumping water from it.

Also known are hydrocarbon recovery technologies from:

vibration and vibration (27 April 1976);

U.S. Pat. 3,952,800, 1977. November 29

U.S. Pat. 4,060,128, 1978. September 19 U.S. Pat. 4,144,689, 1983. November 29 U.S. Pat. 4,416,621);

- accompanying thermal effects (U.S. Pat. No. 4,049,053, September 20, 1997);

magnetic effects (U.S. Patent No. 4,084,638, April 18, 1978; U.S. Patent No. 4,664,978, August 21, 1979).

However, they do not provide for operations such as gasification of aquifers containing gas, formation of reservoirs, formation of new gas fields, etc.

The main disadvantages of the earlier approaches would be:

- when using tanks for underground storage of gas close to consumers, they shall be filled with the gas already received, which has been provisionally transported from receiving areas which are, as a rule, quite far. Thus, such a scheme of gas supply to consumers is related to the construction of gas pipelines, construction of pumping stations, etc., which in turn requires a lot of financial, material, energy, etc. expenses;

- the extraction of water and subsequent gas separation on the surface is in fact a relatively unprofitable operation which involves the transport of large volumes of liquid and other problems caused by the high mineralization of the water;

- gas extraction from the aquifer using pressure relief, whereby water is pumped continuously over a long period (at least one year), has the same drawbacks as the previous example (each well bore out about 15-25x10 barrels per day), slow gas and their partial removal from the horizon.

Other examples characterizing the present state of the art relate to the existing hydrocarbon reserves.

By the way, previously exploited hydrocarbon sites are depleted, and newly opened sites are, as a rule, quite far from industrial areas and other natural gas uses. Moving gas to such areas becomes a difficult and costly task. The formation of new deposits, taking place in the depths of the earth, takes place throughout geological periods.

In connection with this, the industrial extraction of gas from other sources, such as the extraction of gas from aquiferous horizons containing gas, is becoming increasingly important. Such horizons are quite common and can sometimes be found near gas locations. Often they are connected and form huge underground pools, spanning vast areas up to several thousand square kilometers or even more. Their use in gas extraction, including in areas where there are no deposits of natural gas and oil-gas condensates, would allow a significant increase in the volumes of gas received, facilitating the question of gas supply to consumers.

Prior to the present invention, industrial gas extraction from aquifers has not found proper development due to labor fatigue and low efficiency of existing technologies.

The present invention addresses these objects.

Clarification of the Invention

The object of the invention is to provide a way of supplying consumers from gas-saturated aquifers, to increase the volume of gas reserves extracted, and to reduce the expenses related to gas transportation. A further object of the invention is to utilize the natural or artificial elastic oscillations existing in one or another area to reduce the energy cost of producing gas from such horizons.

The desired goal is achieved above the gas saturated aquifer by forming a reservoir and its filling with gas, to perform periodic effects on these gas saturated aquifers. It has been found that it is the combination of various means that allows efficient and reliable extraction of gas from gas-saturated aquifers, storage in its formed tanks and stable supply of gas to consumers.

Periodic effects on the gas-saturated aquifer may be achieved by generating elastic oscillations over a given horizon, for example by means of explosions and / or by the use of an acoustic vibratory and / or seismic source.

Exposure can occur by raising the temperature, for example, by exposure to hot steam in the aquifer (including through a pressurized well) or by using an electric refrigerator when it is introduced into the aquifer, such as a productive well. The thermal effect is expedient when the gas can be in the form of gas hydrates.

Effective exposure to a gas-saturated aquifer may be achieved by electromagnetic fields, such as electric discharges from an electric discharger, or by the use of electrodes in an aqueous bed, for example supplied with a constant voltage, as well as by frequency modulation.

In the case of elastic oscillations and electric current, this affects not only the fluid processes but also the collector properties of the blanket. For example, acting on a gas-saturated aquifer with electrical impulses produces thermal, electromagnetic, physico-chemical effects (e.g., electric current causes electro-lithium phenomena, electro-osmosis, etc.). Elastic perturbations (perturbations) and, first of all, shock waves, which cause clod-manifold splitting, accelerated discharge of released gas into the borehole, and their fuller release from the horizon are obtained.

The periodic effects of the elastic oscillations significantly accelerate the processes of gas release from the aquifer, stimulate and intensify its movement into the capacitors. Fluctuations can also regulate the movement of gas. At low frequency oscillations (0.2-60 Hz), one source of seismic oscillations from the earth's surface can be exposed to multiple gas-saturated aquifers over large areas and depths. They also challenge the maximum gas output.

The periodic degassing effect on the gas-saturated aquifer can be accomplished by coexisting with the aforementioned measures in various combinations and ratios from various sources of exposure depending on the particular operating conditions. In that case, the mechanism and degree of effect of such combined effects on the object is not simply the sum of such individual effects or mechanisms, but rather manifests new qualitative and quantitative effects defined by the specified combinations. Combined effects increase the effectiveness of the technique.

In addition to the effects mentioned, there may be any other technique known in the art that causes gas release from a gas-saturated aquifer.

The periodicity of the effects is determined by leaving the set of conditions, namely: the parameters of the state of the gas-saturated aquifer (including pressure, temLT 3749 B specific volume, specific volume), its composition, physicochemical properties, the relaxation properties of fluids and formations. changes in exposure conditions, collector and other strain characteristics, resonant liner characteristics, tank fill rate and speed, gas selection for user needs, and other factors.

With all of the above effects, gas evolution begins in the gas-saturated aquifer. Gases on this horizon can take many forms: dissolved, free phase, gas bubbles, gas hydrates, and so on. The release of gas from such a horizon is uneven, which is related to their geological structure and filling. This uneven gas release cannot be eliminated by controlling the periodicity of the degassing effect. This unevenness in gas evolution prevents the direct use of the gas released for consumer purposes or the economical transport of it, because of differences in pressure and flow. This requires the use of a set of combined measures.

According to the invention, in addition to the periodic degassing action on the gas saturated aquifer, the formation of at least one 'capacitor' above this horizon is used. Capacitance refers to a specific volume that can accommodate evolved gases, such as underground voids and any appropriate volume of space.

The term formation refers to different operations depending on geological conditions. This may include finding the finished natural subsurface and making it possible to achieve it by drilling with the necessary borehole sealing, additional wall compaction. This may include blasting, or volumizing, thawing permafrost, washing caverns in salt or clay deposits, and the like. Capacitors may also be formed of several, which in turn may be over different gas saturated aquifers, given that these capacitors may be formed by hydrodynamic communication between themselves.

In the process of periodic exposure to gas-saturated aquifer and gas extraction therefrom, the formation of a capacitated reservoir is completed. Likewise, the method does not exclude the possibility of feeding the aquifers above the horizon with gas emitted from the aquifer.

In essence, a new gas field is being formed, which becomes a substantially filled and ever increasing storage tank.

In this case, uneven gas release from a gas-saturated aquifer is of little importance, as is the case with the formation of natural gas sites in the geological process. Meanwhile, the gas accumulations thus formed make it possible to use the gas directly with a sufficiently stable yield.

Significant continuity of gas-saturated aquifers, which are useful in the present invention for industrial gas extraction, allows the selection of specific container-formation regions over these horizons with a known degree of freedom and, accordingly, the periodic effects of degassing on the horizon. Of course, one of these options may be to choose a district close to the potential user to reduce transportation costs.

These options also allow the formation of storage tanks over gas-saturated aquifers where natural or artificial sources of elastic oscillation exist. For example, a seismic-active area or an area close to hydroelectric power stations, railways, military poles, quarries, industrial sites, etc. may be selected. In all cases, in the gas release region, the gas-saturated aquifer and the reservoir are subject to elastic fluctuations from said sources. This reduces the need for the artificial effects described above and at the same time reduces the energy costs of gas extraction.

BRIEF DESCRIPTION OF THE DRAWINGS The figure schematically illustrates an embodiment of the method of the present invention wherein the effect on a gas-saturated aqueous horizon is effected by a local source flowing through a borehole into the horizon.

FIG. 2 depicts an embodiment of a method wherein the effect on a gas-saturated aquifer is accomplished by combining different sources.

FIGURE 3B illustrates an embodiment of the method wherein the reservoir over the gas-saturated aquifer is formed close to natural or artificial sources of oscillation.

Best ways to execute the method

For convenient operation in the area (or selected according to some other criteria), at least one borehole (2) (Fig. 2) is drilled over the gas-saturated aquifer (1). Forms a container (3) for receiving the released gas above the horizon. Means are provided for the further extraction of gas from the storage tank by forming a perforated section of the borehole (4).

This is followed by a degassing effect on the gas-saturated aquifer.

In one embodiment of the invention, the degassing effect on the gas-saturated aqueous horizon is effected by an electromagnetic field formed by electrodes (6) lowered into specially drilled auxiliary wells as shown in Fig. 2.

In another embodiment, the horizon is affected by electrical discharges using an electrical discharge device, schematically shown as a source of local degassing effect (5). The source of the degassing effect may also be an explosive charge cartridge. The effect can also be achieved by using a source of elastic oscillation (7) located on the surface (Fig. 2). In all cases, the efficiency of the effect increases with the difference in pressure, for example due to the partial intake of water through the borehole (2) and the consequent reduction in pressure in the aquifer.

As mentioned above and as shown in Fig. 2, the effects may be combined.

In addition, the formation of reservoirs near natural or artificial sources of elastic oscillation (as schematically shown in Fig. 3) substantially reduces the need for additional special degassing effects, since seismic elastic waves, acting on the gas-saturated aquifer, stimulate and significantly accelerate the release process.

In each of these exposure scenarios, the gas-saturated aquifer begins to release gas. Due to its lower specific gravity compared to that of water, the gas rises upward and accumulates in the reservoir and can be pulled up through the perforated well section.

The method according to the invention was used for a gas-saturated aquifer characterized by the following parameters:

depth of depression 1000-1500 m watery pool power 500m specific volume of dissolved gas 1.5-2 m ³ / kg composition of dissolved gas CH ₄ - 95-98 c ₂ h ₈ -c ₅ h ₁₂ - clod pressure 10-15 MPa the temperature of the pavement 20 ° C density of water 1.011

In the implementation of the method, according to geological intelligence, a structural rise was observed in the operational area. To a depth of 1200 m was drilled a borehole (2), a well-formed capacitor (3) formed by known methods between the clay and sand layers (here it became necessary to seal one of the fractures, which was done by cementing it). The source of oscillation (5) is lowered via cable-rope to the aquifer (1). The vibratory effect according to FIG. the scheme provided. Under the influence of the elastic oscillations, as in the following, the water basin starts to release gas, which due to its lighter relative weight, rises upwards and accumulates in the reservoir and then rises through the modified borehole section (4). surface. Gas extraction from the borehole is adjustable.

An example of a realization method in a seismic-active area is discussed, characterized by the following parameters of a sea-level gas-saturated aquifer: water type - calcium chloride with total mineralization of 91-147 g / l, which has an elevated iodide concentration (1-12 mg / l); bromide concentration (294-426 mg / L). The waters of the dam are characterized by significant gas saturation (2581-3172 cm ³ / l). Water-soluble gas is methane with a concentration of 83-95%. Heavy hydrocarbons shall not exceed 5%. The gas contained 10% nitrogen and up to 0.5% acidic components. The total elasticity of the dissolved gas is 21-51 MPa.

For the realization of the method a borehole with a depth of about 3000 m is drilled. By a known method, a capacitance storage device is formed in which seismic gas is collected. After the standstill period and after the limit has been set, gas-water sampling can be carried out. The rate at which the gas is drawn from the storage tank depends on the movement of the gas-water contact and is determined by its position. Gas selection occurs in the upper part of the tank and uses the back of the well to control the position of the gas-water contact by geophysical methods.

When there is no seismic effect for an extended period of time, additional degassing effects are performed by any of the methods described above.

In this way, this method allows one to simultaneously solve the problem of gas production, collection and storage, all in the proximity of consumers.

Industrial use

The proposed method allows:

- decommissioning volumes of gas that were previously unused and considered indistinguishable;

- formation of gas fields, including those which are closer to the consumers;

- integrate automated management of consumer and business tasks into a single system;

- more effective control over gas exploitation and supply processes;

- reduce the number of service personnel;

- reduce material, energy, financial and other costs, including the reduction of gas and plant transportation losses, construction of gas pipelines and pumping stations, gas storage, etc.

It also reduces the environmental damage associated, for example, with long-distance gas transport. The method may also have other advantages which are apparent from the description given and are apparent to those skilled in the art.

Claims (7)

A method of providing gas to a consumer, comprising forming a gas reservoir, filling it with gas, and providing a gas to the user, characterized in that the reservoir is formed over a gas-saturated aqueous horizon and is filled by periodically acting on a gas-saturated aqueous horizon. 2. The method of claim 1, wherein the periodic effect on the gas-saturated aqueous horizon is effected by the generation of elastic oscillations. 3. The method of claim 1, wherein the reservoir is formed over a gas-saturated aqueous horizon at sites of natural or artificial elastic oscillation. 4. The method of claim 1, wherein the periodic action on the gas-saturated aqueous horizon is effected by a differential pressure. 5. A method according to claim 1, wherein the periodic effect on the gas-saturated aqueous horizon is achieved by increasing the temperature. 6. The method of claim 1, wherein the periodic action on the gas-saturated aqueous horizon is effected by the formation of an electromagnetic field. 7. The method of claim 1, wherein the periodic action on the gas-saturated aqueous horizon is effected by a combination of two or more actions: temperature rise and electromagnetic field action.