CN101699258A - Device and method thereof for testing synthesis and decomposition parameters of hydrate sediment - Google Patents

Abstract

The invention discloses a device for testing synthesis and decomposition parameters of hydrate sediment, which comprises a pressure chamber. The inlet end of the pressure chamber is provided with an air inlet flow meter, an injection pump and an ultrasonic transmitting end; the outlet end of the pressure chamber is provided with an ultrasonic receiving end, a gas-liquid separator and an air outlet flow meter; a TDR measurer and a plurality of detection points are arranged in the inner cavity of the pressure chamber along the length direction thereof; and the axial section where each detection point is positioned is provided with a temperature sensor and a pressure sensor. The device and a method thereof in the invention can acquire multiple basic parameters such as stress strain, seepage, heat, wave, content of each component and the like, and can provide different ambient pressures to simulate the pressure in the actual hydrate sediment stratum, wherein the maximum ambient pressure can reach 30MPa. The gas amount of the hydrate sediment in synthesis and decomposition can be measured by the fine flow meter. The device is lighter, has a small volume and is convenient to move; and the device can be conveniently put into other measurement devices such as CT, chromatograph and spectrometer for microcosmic real-time observation.

Description

Hydrate sediment synthesizes and the device and the method for testing thereof of decomposing parameter testing

Technical field

The present invention relates to the synthetic and decomposition field of hydrate, especially a kind of hydrate sediment synthesizes and the device and the method for testing thereof of decomposing parameter testing.

Background technology

Gas hydrate are under suitably high pressure and suitably low temperature conditions, the cage type crystalline compounds that the class of being made up of water and rock gas is iced.Gas hydrate extensively are distributed in the deepwater environment of continent, ocean and some interior lakes, are a kind of important potential resourcess.

Along with the minimizing of world's oil gas allowable exploitation and the increase of consumption, the urgency of deep sea hydrate exploitation is remarkable day by day.States such as the U.S., Japan, Canada have carried out the work of aspects such as a large amount of phase balance conditions, method of exploration, and have carried out pilot production.

Oil-gas mining, hydrate exploitation or natural conditions variation can cause decomposition of hydrate in the hydrate sediment stratum (abbreviation hydrate sediment).Decomposition of hydrate makes the rock soil medium in the sedimentary deposit lose splicing on the one hand, can change the structure of sedimentary deposit on the other hand, and the gas of generation can increase pore pressure again, thereby the intensity of this sedimentary deposit is reduced.The reduction of hydrate sediment intensity can cause multiple serious disaster, as because the destruction of works in sea that the well head surrounding soil large deformation that causes of decomposition of hydrate causes or the sea bed, as platform topple, oil gas well breaking-up etc.This disaster will produce serious harm to works in the sea bed, but the research of aspects such as its controlled variable and evolutionary process is also lacked very much.It is documented that the norwegian continental shelf edge is 2500～3200 cubic kilometers of sediments owing to slip altogether in the submarine slide (Storegga landslide) that decomposition of hydrate takes place, is the submarine slide of the maximum found so far.A large amount of geologic examinations is that decomposition has taken place hydrate owing to water temperature increase at that time with the reason that the analysis showed that this landslide of generation.The rapid decomposition of hydrate will cause multiple failure modes such as wide-spread decline, and may cause tsunami.

At present in the world seldom for the achievement in research of this problem, about the thermal synthesis in the hydrate sediment and decomposition, seepage characteristic and other mechanical foundation data also lack very much, these parameters are significant for hydrate exploration, exploitation and submarine structure disaster analysis, therefore must obtain the rule of seepage flow and thermal diffusion in the basic parameter of hydrate sediment, synthetic and the decomposable process at first by experiment, and hydrate synthetic with decompose after the intensity etc. on stratum provide foundation for engineering design.

Summary of the invention

Problem at the prior art existence, the object of the present invention is to provide synthetic device and the method for testing thereof of testing of a kind of hydrate sediment with decomposition seepage flow, thermal conductivity and mechanics parameter, this device can obtain multiple basic parameters such as ess-strain, seepage flow, heat, ripple, each component concentration simultaneously, can provide different confined pressures, with the pressure in the simulation actual formation.

For achieving the above object, hydrate sediment of the present invention synthesizes and the device that decomposes parameter testing, comprise the pressure chamber, the entrance point of pressure chamber is provided with charge flow rate meter, liquid charge pump and ultrasound emission end, the endpiece of pressure chamber is provided with ultrasonic receiving end, gas-liquid separation meter and the flowmeter of giving vent to anger, is provided with TDR along its length direction in the inner chamber of pressure chamber and measures and several check points, be provided with temperature sensor and pressure transducer on the shaft section at each check point place.

Further, the inwall of described pressure chamber is provided with rubber membrane and confined pressure loading system, by load confined pressure liquid between the inwall of the outer wall of rubber membrane and described pressure chamber, adjusts the confined pressure in the described pressure chamber.

Further, described ultrasound emission end and ultrasonic receiving end are controlled by ultrasonic controller.

Further, also be provided with temperature-controlling system in the described pressure chamber, come the indoor temperature of controlled pressure by this temperature-controlling system.

Further, described pressure chamber is made by stainless steel.

A kind of method of testing of utilizing said apparatus to test is specially:

1) will test in the native rubber membrane space of inserting in the pressure chamber, form sediment skeleton with certain dry density;

2) the sediment load test is specified confined pressure, record ultrasound parameter, TDR parameter;

3) carry out the mensuration of sediment absolute permeability by the water filling of liquid charge pump constant voltage, and write down its ultrasound parameter, TDR parameter;

4) open the rock gas valve, open temperature-controlled box, control system is fitted fixed temperature, writes down its ultrasound parameter, TDR parameter;

5) according to the experiment setting means synthetic with decompose hydrate sediment, the record hydrate synthetic with decomposable process in the variation of each parameter, treat the balance that hydrate sediment terminal pressure and forefront pressure are stable, stop to test.

Devices and methods therefor among the present invention can obtain multiple basic parameters such as ess-strain, seepage flow, heat, ripple, each component concentration simultaneously, and different confined pressures can be provided, and maximum confined pressure can reach 30MPa, with the pressure in the simulation actual formation.Gas flow in can synthesizing and synthesize and decompose by meticulous flowmeter survey hydrate.This device is lighter, and volume is little, is convenient to move, and can put it into other measurement mechanisms such as CT easily, carries out the microcosmic real-time monitored under chromatograph, the spectrometer.

Description of drawings

Fig. 1 is apparatus of the present invention structural representation;

The thermal conductivity curve map that Fig. 2 records for experiment;

Fig. 3 is the stress-strain relation of experiment measuring.

Embodiment

As shown in Figure 1 to Figure 3, hydrate sediment of the present invention synthesizes and the device that decomposes parameter testing, comprise pressure chamber 1, pressure chamber 1 is made by stainless steel, it can bear the high pressure of 30MPa, be used for fixing sediment sample 19 and the space of confined pressure with carrier fluid is provided, and import and export of various measuring equipments and gas liquid etc. are provided.Pressure chamber 1 is provided with temperature-controlling system 2, temperature measurement system, pressure-measuring system, ultrasound measurement system, TDR measuring system.Wherein temperature-controlling system 2 provides the constant temperature of test demand; Temperature measurement system comprises temperature sensor 3, and temperature sensor 3 is arranged in pressure chamber's inner chamber along on the shaft section of several check points that are provided with on its length direction; Pressure-measuring system comprises pressure transducer 4, and pressure transducer 4 also is arranged in pressure chamber's inner chamber along on the shaft section of several check points that are provided with on its length direction.The entrance point 5 of pressure chamber 1 is provided with inlet valve 6, charge flow rate meter 7, liquid charge pump 8 and ultrasound emission end 9, the endpiece 10 of pressure chamber 1 is provided with outlet valve 11, ultrasonic receiving end 12, gas-liquid separation meter 13 and the flowmeter 14 of giving vent to anger, ultrasound measurement system comprises ultrasound emission end 9, ultrasonic receiving end 12 and ultrasonic controller 15, and ultrasound emission end 9 and ultrasonic receiving end 12 are controlled by ultrasonic controller 15.Temperature measurement system, pressure-measuring system, ultrasound measurement system, TDR measuring system 18 provide respectively hydrate sediment synthetic with decomposable process in the isoparametric variation of saturation degree of point, line, surface, and variation and synthetic and the decomposition region etc. of feeding back hydrate sediment thermal physical property parameter in synthetic and the decomposable process, and the pressure temperature measuring system can provide the pressure and temp field distribution of center vertically, with the synthetic of the thermal physical property parameter of analyzing each material and hydrate with decompose percolation law; Flowmeter is used to control air inlet feed liquor amount, and writes down out instantaneous tolerance and the accumulation total amount of giving vent to anger, and in conjunction with the amount of the water of gas-liquid separation meter record, carries out the mutation analysis of permeability in the sediment and seepage characteristic etc. jointly.

The inwall of pressure chamber 1 is provided with rubber membrane 16 and confined pressure loading system, and the sidewall of pressure chamber 1 is provided with confined pressure liquid load ports 17, by load confined pressure liquid between the inwall of the outer wall of rubber membrane 16 and pressure chamber 1, adjusts the confined pressure in the pressure chamber 1.

The method of testing of utilizing said apparatus to test is specially:

1) will test in the native rubber membrane space of inserting in the pressure chamber, form sediment skeleton with certain dry density;

2) the sediment load test is specified confined pressure, record ultrasound parameter, TDR parameter;

3) carry out the mensuration of sediment absolute permeability by the water filling of liquid charge pump constant voltage, and write down its ultrasound parameter, TDR parameter;

4) open the rock gas valve, open temperature-controlled box, control system is fitted fixed temperature, writes down its ultrasound parameter, TDR parameter;

5) according to the experiment setting means synthetic with decompose hydrate sediment, the record hydrate sediment synthetic with decomposable process in the variation of each parameter, treat the balance that hydrate sediment terminal pressure and forefront pressure are stable, stop to test.

The experimental analysis process:

By the measurement data of temperature, determine that by the heat-conduction equation that contains phase transformation (formula as follows) phase transformation is synthesized and the heat transfer process and the thermal physical property parameter that decompose in the hydrate sediment;

$\frac{\&PartialD;T}{\&PartialD;t}={\mathrm{<figure-callout\; id="2"\; label="a"\; filenames="H2009102362491E0000022.png"\; state="\{\{state\}\}">a</figure-callout>}}^2\frac{{\&PartialD;}^{2}T}{\&PartialD;x^2},$ $a^2=\frac{{\mathrm{\&rho;}}_r{C}_r}{K_r}\frac{K}{\mathrm{\&rho;C}}$

$T\left(s_i\left(t\right)\right)=\frac{T_{\mathrm{Di}}}{T_{\mathrm{Df}}},$ $\frac{\&PartialD;T}{\&PartialD;x}{|}_{s_i+}-\frac{\&PartialD;T}{\&PartialD;x}{|}_{s_i-}=\frac{{\mathrm{\&rho;}}_i\mathrm{\&Delta;H}{\mathrm{\&epsiv;}}_i}{\mathrm{\&rho;}{\mathrm{CT}}_{\mathrm{Df}}}\frac{{\mathrm{ds}}_i}{\mathrm{dt}}$

Analyze by the TDR parameter, determine hydrate synthetic with decomposable process in each phase saturation change, measure in conjunction with temperature, pressure and determine synthetic and decomposition region.

By the ultrasound parameter analysis, determine mechanics parameter such as the modulus and the intensity on stratum by the following formula inverting.

$V_p=\sqrt{\frac{k+4\mathrm{\&mu;}/3}{\mathrm{\&rho;}}},$ $V_s=\sqrt{\frac{\mathrm{\&mu;}}{\mathrm{\&rho;}}},$ ρ＝(1-φ)ρ _ma+φρ _fl

K wherein, μ, ρ is respectively bulk modulus, modulus of shearing and mixture density, φ is a porosity, ρ _MaBe skeletal density, ρ _PlBe pore fluid density.

The TDR analysis result is combined with the ultrasound parameter analysis result, obtain the relation of hydrate saturation degree in hydrate sediment mechanics parameter and the hydrate sediment.

Obtain each permeability mutually in the sediment by the gas of seepage flow discharge and the component analysis of liquid.

K _i＝Q _i/T/A

K wherein _iBe each phase, Q _iBe total discharge rate of each phase, T is the time, and A is a sectional area.

By the overall variation of the water yield, tolerance, the distribution of pore pressure, by the following formula analysis draw hydrate synthetic with decomposable process in change of stress field in the sediment.

σ _e＝σ-p

Wherein, σ _eFor sediment stress, σ are embryo deposit thing stress, p is that increment is pressed in the hole.

Superiority of the present invention is to obtain multiple basic parameters such as ess-strain, seepage flow, heat, ripple, each component concentration simultaneously, and different confined pressures can be provided, and maximum confined pressure can reach 30MPa, to simulate the pressure in the actual hydrate sediment stratum.Gas flow in can synthesizing and decompose by meticulous flowmeter survey hydrate sediment.And apparatus of the present invention are in light weight, and volume is little, are convenient to move, and can put it into other measurement mechanisms such as CT easily, carry out the microcosmic real-time monitored under chromatograph, the spectrometer.

Claims (6)

1. hydrate sediment synthesizes and the device that decomposes parameter testing, it is characterized in that, this device comprises the pressure chamber, the entrance point of pressure chamber is provided with charge flow rate meter, liquid charge pump and ultrasound emission end, the endpiece of pressure chamber is provided with ultrasonic receiving end, gas-liquid separation meter and the flowmeter of giving vent to anger, is provided with TDR along its length direction in the inner chamber of pressure chamber and measures and several check points, be provided with temperature sensor and pressure transducer on the shaft section at each check point place.

2. hydrate sediment as claimed in claim 1 synthesizes and the device that decomposes parameter testing, it is characterized in that, the inwall of described pressure chamber is provided with rubber membrane and confined pressure loading system, by between the inwall of the outer wall of rubber membrane and described pressure chamber, loading confined pressure liquid, adjust the confined pressure in the described pressure chamber.

3. hydrate sediment as claimed in claim 1 is synthetic and decompose the device of parameter testing, it is characterized in that described ultrasound emission end and ultrasonic receiving end are controlled by ultrasonic controller.

4. hydrate sediment as claimed in claim 1 is synthetic and decompose the device of parameter testing, it is characterized in that, also is provided with temperature-controlling system in the described pressure chamber, comes the indoor temperature of controlled pressure by this temperature-controlling system.

5. hydrate sediment as claimed in claim 1 is synthetic and decompose the device of parameter testing, it is characterized in that described pressure chamber is made by stainless steel.

6. method of testing of utilizing said apparatus to test is specially:

1) will test in the native rubber membrane space of inserting in the pressure chamber, form sediment skeleton with certain dry density;

2) the sediment load test is specified confined pressure, record ultrasound parameter, TDR parameter;

3) carry out the mensuration of sediment absolute permeability by the water filling of liquid charge pump constant voltage, and write down its ultrasound parameter, TDR parameter;

4) open the rock gas valve, open temperature-controlled box, control system is fitted fixed temperature, writes down its ultrasound parameter, TDR parameter;

5) according to the experiment setting means synthetic with decompose hydrate sediment, the record hydrate sediment synthetic with decomposable process in the variation of each parameter, treat the balance that hydrate sediment terminal pressure and forefront pressure are stable, stop to test.

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