CN1632509A - Method and equipment for extracting hydrocarbon gas from seabed sediment on board - Google Patents

Abstract

This invention relates to a ship carrying and extracting the sea deposition of hydrocarbon gas method and its device, which belongs to hydrocarbon gas earth chemical analysis device. It comprises hydrocarbon gas extraction method and its total hydrocarbon process device of usage method. The method is to make vacuum and control temperature and join chemical agent under seal conditions and through automatic disturbing and to create a condition to make the balance move the absorption direction and generate hydrocarbon gas with multiple phases. The device comprises four parts of liquid path, gas path, automatic control and operation bench.

Description

Method and equipment for extracting hydrocarbon gas from seabed sediment on board

technical field

The invention relates to a method and equipment for extracting hydrocarbon gas from seabed sediment carried by a ship, which belongs to geochemical analysis equipment for hydrocarbon gas, and the patent classification number is C10G.

Background technique

At present, the offshore geochemical detection basically follows the onshore method, that is, the direct or indirect geochemical anomalies caused by hydrocarbon micro-leakage in oil and gas reservoirs are detected by conventional means, such as the alkane component anomalies in seabed sediments, etc.

For offshore oil and gas geochemical exploration, there is an urgent need for a convenient, simple, and fast on-board on-site rapid detection equipment that can meet geological tasks, realize on-site processing, testing, and comprehensive interpretation of marine sediment samples, so as to adapt to offshore Exploration work needs.

Hydrocarbon gas is the main indicator of oil and gas geochemical exploration, and there are various occurrence states of hydrocarbon gas in near-surface sediments. The analysis results prove that the hydrocarbon gases (mainly methane) in the sediments and pore water of oil and gas reservoirs and natural gas hydrate gas reservoirs are mainly dissolved hydrocarbons (water-soluble hydrocarbons), free hydrocarbons, adsorbed hydrocarbons, absorbed hydrocarbons and occluded hydrocarbons. (acidolysis of hydrocarbons) in the form of occurrence.

Various hydrocarbon gases in the above forms constitute the hydrocarbon index series for searching for natural gas hydrates, natural gas reservoirs and oil reservoirs by geochemical methods. However, before the trace detection and analysis of hydrocarbon indicators, it is first necessary to prepare gases from various media samples. The gas extraction sample preparation methods currently used at home and abroad are mainly as follows:

(1). Acidolysis hydrocarbon degassing method

The acid hydrolysis method mainly detects the hydrocarbon gas wrapped in carbonate minerals, which is the main method for determining the hydrocarbon gas index after the chemical prospecting samples are dried and pulverized:

A. Atmospheric pressure heating degassing method

The physical process of heating releases hydrocarbon gases from deposits. The selected temperature is based on not causing chemical changes in the sample or avoiding the cracking of non-volatile polymer compounds to produce new hydrocarbons. Under normal pressure conditions, when the temperature is constant, the amount of hydrocarbon gas increases with the heating time until it becomes stable.

B. Vacuum heating acid solution degassing method

Control the negative pressure at about 600~700mmHg (about -80~-101kPa), heat to boiling (about 50~60°C), and add a certain concentration of acid (hydrochloric acid or phosphoric acid) solution.

C. Vacuum constant temperature acid degassing method

The method vacuumizes and depressurizes and the acid hydrolysis steps are the same as the aforementioned method. In order to unify the test conditions and eliminate the influence of indoor natural temperature difference in different seasons on the amount of degassing, a constant temperature of 35°C water bath was adopted.

(2). Thermal release hydrocarbon degassing method

The pyrohydrocarbon degassing method adopts the method of heating and heating to desorb and release the hydrocarbons occluded in the silicate minerals and the hydrocarbon gases adsorbed on the surface of the mineral particles by chemical and physical effects at low temperature.

(3). Degassing preparation method of water-soluble gaseous hydrocarbon samples

Hydrocarbon gas dissolved in water is uncharged, it can neither polarize the nearby water molecules nor produce electrolytic reaction with the electrolyte in water, it exists in the form of molecules in the "pores" between water molecules. In other words, the dissolution and occurrence of these hydrocarbon gases depend on the structure of water. Based on the above characteristics, the negative pressure heating method was selected through experiments to weaken the interaction between electrolytes, ions and water molecules, promote the Brownian motion of water molecules, and destroy the combination of water molecules, thereby reducing the solubility coefficient of the gas. Release hydrocarbon gases.

(4). Free hydrocarbon degassing technology

This method directly measures the trace amount of hydrocarbon gas that migrates vertically without any chemical treatment and transformation, and more truly reflects the original composition of oil and gas. This part of hydrocarbon gas can be decomposed by mechanical methods such as static or vibration in the device.

To sum up, the traditional sample preparation method for hydrocarbon gas in geochemical exploration is carried out one by one according to the occurrence state of hydrocarbons. Although it has the advantages of refinement and other aspects, it cannot adapt to the conditions of on-board measurement in the ocean. Because the original degassing equipment is an independent degassing and analysis test room (room) for each hydrocarbon gas, it is obviously inappropriate to transfer such a variety of methods and huge equipment to the ship for on-board measurement ; The hydrocarbon gas analysis laboratory on land is static and fixed, but at sea, specific conditions such as anti-vibration, anti-shake, and moisture resistance must be considered; Existence, it is impossible to spread out samples for drying, crushing, sieving, etc. like on land, that is to say, it is difficult to provide sample processing workshops and facilities to avoid pollution on board.

In addition, if the sample is taken to a land laboratory for analysis, some hydrocarbon gases will inevitably be lost before the sample is delivered to the laboratory, and even some hydrocarbon gases are almost completely dissipated (such as free hydrocarbons, etc.), The longer period will bring pollution, and the measured results will have larger errors. In addition, the best exploration and sampling opportunities will be missed. Therefore, it is necessary to develop new on-site hydrocarbon gas preparation methods and devices in marine shipborne geochemical exploration.

Contents of the invention

The object of the present invention is to provide a method and equipment for extracting hydrocarbon gases from seabed sediments on board a ship, to realize on-site processing, testing, and comprehensive interpretation of marine sediment samples, as well as a method that can be equipped on board 1. An all-hydrocarbon preparation apparatus for extracting hydrocarbon gas applicable to the method. It is convenient, simple, fast and practical to use the instrument.

The technical scheme of the method and equipment of a kind of ship-borne extraction hydrocarbon gas in seabed sediment of the present invention is as follows:

A method for ship-borne extraction of hydrocarbon gas in seabed sediments, characterized in that the method for extracting hydrocarbon gas is as follows:

A. Release free hydrocarbons and weakly adsorbed hydrocarbons under negative pressure conditions

Main equipment and materials: full hydrocarbon preparation instrument, miniature high-pressure vacuum pump, alkali solution, water gas preparation steps:

(1) vacuumize the pipeline in the degasser;

(2) sealing;

(3) sampling (equivalent to 50 grams of weight), placed in a volumetric flask;

(4) Connect the degassing pipeline;

(5) Vacuum again (controlled at 760mm) to form a negative pressure;

(6) Stand still for 5 minutes, shake the volumetric flask every 1 minute;

(7) The alkaline solution expels the released gas and moves it to the spiral enrichment tube;

(8) Read the amount of degassing, extract the degassed gas, and transfer it to the gas storage container;

(9) emit alkali solution;

(10). Pour out the sample cleaning capacity

B. Negative pressure and normal temperature (40°C) remove dissolved gas from sediment pore water

Main equipment: the same equipment used for free hydrocarbons;

Step: with free hydrocarbons, last for 3 minutes;

C. Negative pressure heating (40-80°C) acid hydrolysis to release the occluded hydrocarbons in the sediment

Main equipment: prepare a certain proportion of hydrochloric acid (or phosphoric acid), put it in a container, and other equipment used for free hydrocarbons;

Steps: Same as free hydrocarbons, except that after vacuuming, add acid to titrate the sample until no bubbling, heat to (40-80°C) and let it stand for 5 minutes, and shake the container once every minute;

D. Negative pressure heating (180°C) removes the hydrocarbons absorbed in the sediment

Main equipment: same as free hydrocarbon;

Steps: Same as free hydrocarbons, except heating to 180°C for 3 minutes;

E. For the various hydrocarbon gases in the above samples, use a total hydrocarbon preparation device to synthesize and prepare, that is, to remove the hydrocarbon gases in the aforementioned five phases at one time.

Main equipment and materials: full hydrocarbon preparation instrument, miniature high-pressure vacuum pump, alkali solution, acid solution, water;

Preparation steps: After the above five kinds of hydrocarbon gases are removed according to their respective preparation steps, they will not be extracted or transferred, and will be kept in the enrichment tube until all the hydrocarbon gases are removed, and the comprehensive hydrocarbon gas will be obtained, and then read Test the amount of degassing, then extract and transfer to a gas storage container.

The method for extracting hydrocarbon gases from seabed sediments carried by a ship is characterized in that the total error between the total amount of degassing and the degassing separately should be controlled at less than 5% (volume ratio).

A ship-borne full-hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments is characterized in that the preparation instrument is composed of four parts: liquid circuit, gas circuit, automatic control and console components; the preparation instrument has two sets of complete The same liquid path and gas path; the liquid path includes the pipelines and vessels that flow through; the pipeline is connected with electromagnetic reversing valves, tee pipes, enrichment tubes, flasks for samples, etc.; the gas path includes vacuum Air pump, buffer bottle, pressure gauge, electromagnetic reversing valve, automatic temperature control furnace, flask for sample, etc.; the automatic control part includes power supply, heating furnace temperature control system, electromagnetic reversing valve control circuit, automatic control circuit, etc.; operation Table components include installation box, console, wires, wiring ports, etc.

The ship-borne full-hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments is characterized in that the automatic temperature control furnace is fixed in the box, and the sample-loading flask is placed in an automatic temperature control furnace. In the furnace, there are two input pipes communicating with the inside of the flask, one is a ventilation pipe and the other is an infusion pipe; the ventilation pipe is connected to the enrichment pipe through a three-way valve, and the other is connected to a pressure gauge through a solenoid valve. After that, the buffer bottle is connected to the buffer bottle, which is connected with a vacuum pump; the enrichment pipe also has a nozzle connected to a solenoid valve and is connected with the alkali delivery pipe; The acid pipe is connected, and the other road is connected with the water pipe after passing through a solenoid valve; the acid pipe, the alkali pipe, and the water pipe are respectively drawn from three 3500 ml conical flasks above the instrument.

The electromagnetic reversing valve described above, the valve body is made of acid and alkali-resistant polyetheretherketone material; normally closed type; when the solenoid valve is powered on, the valve core moves upward, and the channel inlet and channel outlet are connected through the groove at the bottom of the valve core. path.

The piping in the equipment is made of polytetrafluoroethylene material resistant to acid and alkali; the diameter of the piping and valves is less than 4 mm.

The device can operate according to the automatic control program, and all steps are determined by the single-chip microcomputer according to the set program.

The device can also be converted to manual control.

To sum up, free hydrocarbons, water-soluble hydrocarbons and adsorbed hydrocarbons are easy to escape with changes in environment and conditions, and all three of them can easily escape from sediments under pressure-changing conditions. According to this characteristic, creating In a suitable environment, select the appropriate negative pressure range and temperature range, and this part of hydrocarbon gas can be released at one time to achieve the purpose of synthetic degassing.

The storage state of occluded hydrocarbons and absorbed hydrocarbons in sediments is relatively stable, and they are firmly combined with carbonate rocks and silicates. As long as the conditions of negative pressure, heating and acid addition are mastered, they can be processed in the total hydrocarbon preparation device at one time. come out. The total error of degassing total amount and separate degassing is controlled at less than 5% (volume ratio).

The synthesis and preparation of various hydrocarbon gases in the above samples, that is, the removal of the aforementioned five phases of hydrocarbon gases at one time, used the all-hydrocarbon preparation device of the present invention.

The sample hydrocarbon gas preparation and extraction device of the present invention, that is, the total hydrocarbon preparation instrument, is to create a condition that makes the balance move toward the desorption direction by automatically disturbing the vacuum, controlling the temperature rise, adding chemical reagents and other processes under sealed conditions, and can Desorb hydrocarbon gases in various phases. Therefore, installing a full hydrocarbon preparation instrument on board is equivalent to replacing the degassing equipment on land. For each type of hydrocarbon gas, an independent degassing and analysis test room (room) will be carried out, and so many The method and huge equipment are moved to the ship for on-board measurement. In addition, the whole hydrocarbon preparation instrument of the present invention is also specially designed with shockproof and fixing measures for the equipment, which increases the reliability of offshore operations. Therefore, the total hydrocarbon preparation instrument of the present invention is an ideal ship-borne equipment for extracting hydrocarbon gases in seabed sediments. The instrument is convenient, simple, fast and practical.

Description of drawings

Fig. 1 is a block diagram of the work flow of a method for extracting hydrocarbon gases from seabed sediments carried by a ship according to the present invention.

Fig. 2 is a working principle diagram of a ship-borne all-hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments according to the present invention.

Fig. 3 is a schematic diagram of the general assembly structure of a ship-borne all-hydrocarbon preparation device for extracting hydrocarbon gases from seabed sediments according to the present invention.

Figure 4 is a schematic diagram of the c-c cross-sectional structure in Figure 3

Figure 5 is a schematic diagram of the d-d cross-sectional structure in Figure 3

Fig. 6 is the schematic diagram of the operating table of a kind of ship-borne total hydrocarbon preparation instrument for extracting hydrocarbon gas in seabed sediments of the present invention

Fig. 7 is a structural schematic diagram of an electromagnetic reversing valve of a ship-borne total hydrocarbon preparation device for extracting hydrocarbon gases from seabed sediments according to the present invention.

Fig. 8 is a program flow chart of a single-chip microcomputer for a ship-borne total hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments according to the present invention.

Fig. 9 is a schematic diagram of a control panel of a ship-borne total hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments according to the present invention.

Fig. 10 is a structural diagram of a control panel of a ship-borne total hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments according to the present invention.

Fig. 11 is a circuit control principle block diagram of a ship-borne total hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments according to the present invention.

Specific implementation instructions

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Methods of Hydrocarbon Gas Extraction

A. Release free hydrocarbons and weakly adsorbed hydrocarbons under negative pressure conditions

Principle: Free hydrocarbons and weakly adsorbed hydrocarbons are gases in a dynamic equilibrium state under normal pressure environments. When the pressure conditions are changed, that is, under negative pressure conditions, they will escape freely from the pores of sediments or the surface of mineral particles.

Main equipment and materials: full hydrocarbon preparation instrument, quartz volumetric flask, miniature high-pressure vacuum pump, alkali solution, sealing liquid,

Gas preparation steps:

(1). Vacuumize the pipeline in the degassing device;

(2). Sealing;

(3). Sampling (equivalent to 50 grams of weight) is placed in a volumetric flask;

(4). Connect to the degassing pipeline;

(5). Vacuum again (controlled at 760mm) to form a negative pressure;

(6). Stand still for 5 minutes, shake the volumetric flask once every 1 minute;

(7). The alkaline solution expels the released gas and moves it to the spiral enrichment tube;

(8). Read the amount of degassing, extract the degassed gas, and transfer it to the gas storage container;

(9). Release alkali solution;

(10). Pour out the sample to clean the volumetric flask.

B. Negative pressure and normal temperature (40°C) remove dissolved gas from sediment pore water

Principle: When the temperature and pressure change, Brownian motion is caused, which changes the internal structure of water molecules and the arrangement of hydrogen and oxygen ions, thereby releasing hydrocarbon gas.

Main equipment: same as free hydrocarbon

Procedure: with free hydrocarbons for 3 minutes.

C. Negative pressure heating (40-80°C) acid hydrolysis to release the occluded hydrocarbons in the sediment

Principle: The occluded hydrocarbon refers to the hydrocarbon gas that exists in carbonatite and its cement. Under the condition of negative pressure, the carbonatite structure is destroyed by adding acid to release the occluded hydrocarbon.

Main equipment: Prepare a certain proportion of hydrochloric acid (or phosphoric acid), put it in the container, and the others are the same as free hydrocarbons.

Steps: Same as free hydrocarbons, except that after vacuuming, add acid to titrate the sample until no bubbles, heat (40-80°C) and let stand for 5 minutes, and shake the container every one minute.

D. Negative pressure heating (180°C) removes the hydrocarbons absorbed in the sediment

Principle: Under negative pressure conditions, heating destroys the mineral structure, allowing the absorbed hydrocarbons present in the silicates to escape.

Steps: Same as free hydrocarbons, except heating to 180°C for 3 minutes.

E. Synthesize and prepare various hydrocarbon gases in the above samples, and use the all-hydrocarbon preparation instrument of the present invention to remove the aforementioned five phases of hydrocarbon gases at one time.

Main equipment and materials: full hydrocarbon preparation instrument, miniature high-pressure vacuum pump, alkali solution, acid solution, water;

Preparation steps: After the above five kinds of hydrocarbon gases are removed according to their respective preparation steps, they will not be extracted or transferred, and will be kept in the enrichment tube until all the hydrocarbon gases are removed, and the comprehensive hydrocarbon gas will be obtained, and then read Test the amount of degassing, then extract and transfer to a gas storage container. The workflow block diagram of the total hydrocarbon preparation instrument is shown in Figure 1.

Fig. 2 is a working principle diagram of a ship-borne all-hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments according to the present invention. Fig. 3 is a schematic diagram of the assembly structure of the full hydrocarbon preparation instrument. In the figure, the preparation instrument is composed of four parts: liquid circuit, gas circuit, automatic control and console components; the preparation device has two sets of identical liquid circuit part and gas circuit part; the liquid circuit part includes the flowing pipeline and Vessel; the pipeline is connected with electromagnetic reversing valve 7, three-way pipe 8, enrichment pipe 4, etc.; the gas circuit part includes vacuum pump 1, buffer bottle 2, pressure gauge 5, electromagnetic reversing valve 7, automatic temperature control Furnace 6, sample flask 3, etc.; the automatic control part includes power supply, heating furnace control system, electromagnetic reversing valve control circuit, automatic control circuit, etc.; the console components include equipment installation box 9, console 10, wires, Wiring port, etc. (see Figure 4, Figure 5).

Most of the experimental operations can be run automatically by controlling the solenoid valve 7 and the temperature-controlled furnace 6 . The main hardware device of automatic control is in the control console 9 separated from the main body of the instrument. When working, the experimenter faces the panel of the control console. (Figure 6).

In the complete hydrocarbon preparation instrument, the automatic temperature control furnace 6 is fixed in the box body 9, and the flask 3 containing the sample is placed in the automatic temperature control furnace 6. There are two input pipes communicating with the inside of the flask 3, one It is a ventilation tube, and one is an infusion tube; the ventilation tube communicates with the enrichment pipe 4 through a three-way valve 8m all the way, and the other way is connected to the buffer bottle 2 after a solenoid valve 7a is connected to a pressure gauge 5, and the buffer bottle 2 Connected with a vacuum pump 1; the enrichment pipe 4 has another mouth connected to a solenoid valve 7c and then connected to the alkali delivery pipe; the infusion pipe passes through a three-way valve 8n, and one way passes through a solenoid valve 7d to connect with the acid delivery pipe connected, and the other way is connected with the water delivery pipe after passing through a solenoid valve 7e. Acid delivery pipe, alkali delivery pipe and water delivery pipe are respectively drawn from three 3500 ml Erlenmeyer flasks above the instrument. (Figure 4, Figure 5).

Electromagnetic reversing valve 7 uses the attraction force of electromagnet to control the movement of valve core 72 to realize the reversing of the liquid circuit. The iron core material of conventional electromagnetic valve is generally made of overall industrial pure iron, but the volume is relatively large and the precision is not high. , not suitable for acidolysis degassing device. The full hydrocarbon preparation instrument adopts a two-position two-way electromagnetic reversing valve 7; the valve body 71 is made of acid and alkali-resistant polyetheretherketone material; normally closed; when the electromagnetic valve is powered on, the valve core 72 moves upward, and the channel inlet 75 and The channel outlet 76 is connected to a channel through the groove 74 at the bottom of the valve core 72 . Small and flexible, it can be easily fixed inside the instrument. The electromagnet uses 12V DC power supply, and the switches of all electromagnetic reversing valves are controlled by the single-chip microcomputer control circuit system to ensure the sequential execution of the working procedures. The schematic diagram of the solenoid valve structure is shown in Figure 7.

The power supply of the automatic temperature control furnace (purchased product) is directly drawn from the main power supply, and the power supply is directly connected to the input port of the temperature control furnace. A double-layer resistivity furnace is used, which is composed of temperature control, heat preservation, and temperature measurement systems. There is a gas eddy current device in the furnace body. In the furnace, eddy currents with different directions are formed to form agitated thermal fluid, so as to achieve the purpose of uniform temperature in the furnace. The technical parameters are as follows:

1. Temperature control sensitivity reaches ±5°C

2. The average temperature difference of different parts in the furnace is 1°C, and the maximum error is 2°

3. It has good stability and meets the requirements of gas preparation.

4. The voltage used is 220V, the frequency is 50Hz, and the power is 3000W.

5. Relative humidity <80%.

The pipes and valves in the equipment are made of acid and alkali-resistant polytetrafluoroethylene materials; the pipe diameter is less than 4 mm.

The device can run according to the program of automatic control, and all steps are set by the single-chip microcomputer according to the program: the program flow of the single-chip microcomputer is shown in Figure 8.

The whole hydrocarbon preparation instrument uses 220V power input, 24V power output, and the current is 3A. The voltage is converted into 5V and 15V by the voltage conversion module board, and sent to the control board and solenoid valve respectively (see Figure 9). The input of time data, and then, make control action on the corresponding solenoid valve; play a control role on temperature control. Keyboard and nixie tube control chip 82 is HD7279A, and it implants program together with single-chip microcomputer, realizes the function to user data input and nixie tube output. Two pieces of 74LS04 (87, 88) produce inversion to the control signal, and play the role of consistent control pulse phase.

A piece of CD4051 (86) is an analog switch. The single-chip microcomputer realizes the control of the analog switch with two control signals. The analog switch has 4 outputs (only 3 are used).

E1-E11 are 11 triodes 83, and JD1-JD11 are 11 Darlington tubes 84, which control the functions of 11 electromagnetic valves 85 together.

The Keyboard interface 89 is connected with the signal line of the keyboard board to realize the control function of the keyboard operation. Display interface 90 is connected with digital display part signal on the keyboard board to realize the control function of digital display of operation steps and temperature control. (See Figure 10, Figure 11)

Fig. 3 is the structural sectional view of the whole hydrocarbon preparation instrument, is divided into front and rear two parts by partition, solenoid valve and tee pipe are all placed behind the partition (Fig. 4, Fig. 5,), and main instrument is placed on the front.

The device can also be converted to manual control.

The operation steps of the whole hydrocarbon preparation instrument are as follows:

1. Open the solenoid valve 7a, press the pump 1 switch, and vacuum the pipelines and containers in the instrument;

2. When the pressure gauge 5 indicates a vacuum, turn off the air pump 1. At this time, the enrichment tube 4 in the instrument, the flask 3 containing the sample, and each pipeline are in a vacuum-tight state;

3. Open the solenoid valve 7c, the alkaline solution will be automatically injected into the enrichment pipe 4 due to the pressure difference, and when the liquid level reaches II, close the live solenoid valve 7c;

4. Turn on the automatic temperature control furnace 6, heat the flask to the temperature (80° C.), and keep it for 10 minutes. At this time, the sample will release pyrohydrocarbons and a large amount of CO2 gas, and the generated gas enters the spiral tube of the enrichment tube 4 from the flask 3 along the pipeline, and the gas pushes the liquid in the tube to spiral upward, and finally reaches the liquid in the enrichment tube 4. Top position, during which CO2 is absorbed by the lye;

5. Open the solenoid valve 7d, hydrochloric acid is automatically added to the flask 3, and then close the solenoid valve. At this time, a large amount of CO2 gas and acidolysis hydrocarbon gas will be produced in the reaction between the sample and hydrochloric acid, the same principle as step 4, and finally the hydrocarbon gas reaches the top of the enrichment tube 4

6. After the sample in the flask 3 has reacted completely, open the solenoid valve 7e, water is automatically added to the flask 3 until the flask is filled up, so that the gas remaining in the flask 3 after the reaction is also driven into the top of the enrichment tube 4 ;

7. Open the electromagnetic valve 7c, and the lye is injected into the enrichment pipe 4 again. After the pressure difference inside and outside the enrichment pipe is zero, the gas volume obtained above the enrichment pipe 4 is the volume of hydrocarbon gas extracted from the sample. It is analyzed by gas chromatography;

After the above steps are finished, open the solenoid valve 7f, discharge the lye in the enrichment pipe 4 to the I position, and wait for the next sample to be operated.

The ship-borne method and equipment for extracting hydrocarbon gases in seabed sediments of the present invention realizes on-site testing, processing, comprehensive interpretation of marine sediment samples and on-site determination of hydrocarbon anomalies; 1. A total hydrocarbon preparation instrument suitable for this method and capable of extracting hydrocarbon gases; it replaces the degassing equipment in the prior art and can perform on-board measurement, and is an ideal offshore operation instrument. It is convenient, simple, fast and practical to use the instrument. The purpose of the invention has been achieved, and it has an inventive step. Technical solutions identical to the concept of the present invention are within the protection scope of the claims.

Claims (7)

1. A method for extracting hydrocarbon gas in the seabed sediment carried by a ship, is characterized in that, the method for extracting hydrocarbon gas is as follows: A. Release free hydrocarbons and weakly adsorbed hydrocarbons under negative pressure conditions Main equipment and materials: full hydrocarbon preparation instrument, miniature high-pressure vacuum pump, alkaline solution, water; Gas preparation steps: (1) vacuumize the pipeline in the degasser; (2) sealing; (3) sampling (equivalent to 50 grams of weight), placed in a volumetric flask; (4) Connect the degassing pipeline; (5) Vacuum again (controlled at 760mm) to form a negative pressure; (6) Stand still for 5 minutes, shake the volumetric flask every 1 minute; (7) The alkaline solution expels the released gas and moves it to the spiral enrichment tube; (8) Read the amount of degassing, extract the degassed gas, and transfer it to the gas storage container; (9) emit alkali solution; (10) Pour out the sample cleaning volumetric flask. B. Negative pressure and normal temperature (40°C) remove dissolved gas from sediment pore water Main equipment: the same equipment used for free hydrocarbons; Step: with free hydrocarbons, last for 3 minutes; C. Negative pressure heating (40-80°C) acid hydrolysis to release the occluded hydrocarbons in the sediment Main equipment: prepare a certain proportion of hydrochloric acid (or phosphoric acid), put it in a container, and other equipment used for free hydrocarbons; Steps: Same as free hydrocarbons, except that after vacuuming, add acid to titrate the sample until no bubbling, heat (40-80°C) and let it stand for 5 minutes, and shake the container once every minute; D. Negative pressure heating (180°C) removes the hydrocarbons absorbed in the sediment Main equipment: same as free hydrocarbon; Steps: Same as free hydrocarbons, except heating to 180°C for 3 minutes; E. Use a total hydrocarbon preparation instrument to synthesize and prepare various hydrocarbon gases in the above samples, that is, remove the hydrocarbon gases in the aforementioned five phases at one time. Equipment and materials: full hydrocarbon preparation instrument, miniature high-pressure vacuum pump, alkali solution, acid solution, water; preparation steps: after the above five kinds of hydrocarbon gases are released from the hydrocarbon gas according to their respective preparation steps, they are not extracted or transferred, and are kept in the enrichment In the tube, until all the hydrocarbon gas is completely removed, the comprehensive hydrocarbon gas is obtained, and then the experimental degassing amount is read, and then extracted and transferred to the gas storage container. 2. the method for extracting hydrocarbon gas in a kind of shipboard according to claim 1, is characterized in that, the total error of degassing total amount and separate separate degassing will be controlled at less than 5% (volume ratio) . 3. A ship-borne full-hydrocarbon preparation instrument for extracting hydrocarbon gases from seabed sediments, characterized in that the preparation instrument is composed of four parts such as liquid circuit, gas circuit, automatic control and console parts; the preparation instrument has two The same set of liquid circuit part and gas circuit part; the liquid circuit part includes the pipelines and vessels flowing through; the pipeline is connected with electromagnetic reversing valve, three-way pipe, enrichment tube, flask for sample, etc.; the gas circuit Part includes vacuum pump, buffer bottle, pressure gauge, electromagnetic reversing valve, automatic temperature control furnace, flask for sample, etc.; automatic control part includes power supply, heating furnace control system, electromagnetic reversing valve control circuit, automatic control circuit etc.; console components include installation box, console, wires, wiring ports, etc. 4. a kind of shipboard according to claim 3 extracts the all-hydrocarbon preparation instrument of hydrocarbon gas in seabed sediment, it is characterized in that, described automatic temperature control furnace is fixed in casing, and described adornment sample The flask is placed in an automatic temperature control furnace, and there are two input pipes communicating with the inside of the flask, one is a ventilation pipe and the other is an infusion pipe; The solenoid valve is connected to a pressure gauge and then connected to a buffer bottle, and the buffer bottle is connected to a vacuum pump; the enrichment pipe also has a nozzle connected to a solenoid valve and then connected to the alkali delivery pipe; the infusion pipe passes through a three-way valve all the way through One solenoid valve is connected to the acid pipe, and the other is connected to the water pipe after passing through a solenoid valve; the acid pipe, alkali pipe, and water pipe are respectively drawn from three conical flasks placed above the instrument. 5. A kind of ship-borne total hydrocarbon preparation instrument for extracting hydrocarbon gases in seabed sediments according to claim 3, characterized in that, the electromagnetic reversing valve; the valve pump body adopts acid-resistant and alkali-resistant polyether ether Ketone material; normally closed type; when the solenoid valve is energized, the valve core moves upward, and the channel inlet and channel outlet are connected to form a passage through the groove at the bottom of the valve core. 6. the whole hydrocarbon preparation instrument of a kind of ship-borne extraction hydrocarbon gas in seabed sediment according to claim 3, it is characterized in that, pipeline adopts acid-resistant, alkali-resistant polytetrafluoroethylene material in the described equipment; The diameter of the pipe and valve is less than 4mm. 7. the whole hydrocarbon preparation instrument of a kind of ship-borne extraction hydrocarbon gas in seabed sediment according to claim 3, it is characterized in that, described equipment can run by the program of automatic control, and all steps are by single-chip microcomputer by setting program; the preparation apparatus can also be converted to manual control.

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