CN106596400B - A kind of evaluating apparatus and experimental method of second contact surface bonding quality of cementing the well - Google Patents

Abstract

The invention discloses an evaluation device and an experimental method for the cementation quality of the second interface of well cementing. The second interface is the cement-formation interface. Due to the low-permeability characteristics of the downhole interlayer and cement, the fluid in the formation plays a key role in sealing Therefore, the root cause of channeling at the second interface is the poor bonding quality between the formation interlayer and cement, so the evaluation of the cementation quality at the second interface of cementing mainly considers the bonding between the formation interlayer and cement. This device aims to solve this problem, but at the same time it can also evaluate the bonding of cement to other formations. The present invention generally adopts the real rock core collected at the drilling site to carry out experiments to simulate the site interface cementation to the greatest extent. The experimental principle is reliable, and the experimental results and analysis can provide important references for the evaluation of the cementing quality of the second interface of the cementing cement and provide engineering design. important basis.

Description

An evaluation device and experimental method for the cementation quality of the second interface of well cementing

technical field

The invention belongs to the technical field of evaluation of the second cementing interface of oil and gas well cementing, that is, the interface between the formation and the cement sheath, and in particular relates to an evaluation device and an experimental method for the cementing quality of the second cementing interface of well cementing.

Background technique

The quality of cementing affects the safe and stable production in the later stage and the feasibility of various stimulation measures. The second interface of cementing, that is, the cemented interface between the formation and the cement sheath, due to the presence of relatively loose mud cake and formation fluid, makes the cement sheath easy to peel off after solidification, and the cementation strength decreases. Compared with the first interface, layer channeling is more likely to occur. Therefore, the anti-gas channeling ability of the second interface is a problem that needs more attention.

The evaluation of the cementation status of the second interface is an urgent problem to be solved in the evaluation of cementing quality, and it is difficult to give specific evaluation results by common logging techniques. At present, the indoor experimental evaluation is mainly determined by two aspects, one is the shear bond strength, and the other is the hydraulic bond strength. There are many studies on the former, such as Yang Zhenjie (Yang Zhenjie, Liang Hongjun, Li Feng, etc. Cementing Interface Bond Strength Tester: CN202381076U[P].2012.), Cheng Rongchao (Cheng Rongchao, Bu Yuhuan, Wang Ruihe. BF Research on cementing performance of slag improving cement interface[J]. Natural Gas Industry, 2007, 27 (2): 63-66.) etc. have used this principle to carry out the research on the second interface cementation evaluation, but using this principle to test The results obtained cannot directly give the formation channeling pressure that the cemented surface can bear, and the relationship between the cementation strength and the anti-channeling ability cannot be established. Intensity can still be great. It can be seen that there are problems in this evaluation method. The latter uses hydraulic cement strength evaluation, which essentially evaluates the anti-channeling ability of the interface, and uses the channeling pressure as an index to evaluate the anti-channeling ability of the cementing interface. In line with the downhole situation, the evaluation method and the obtained parameters have direct guiding significance. Gu Jun (Gu Jun, Yang Weihua, Qin Wenzheng, et al. Research on the evaluation method of the sealing ability of the second interface of cementing[J]. Acta Petroleum Sinica, 2008,29(3):451-454.) proposed a method for evaluating the second interface However, this method uses artificial cores and cannot fully simulate the formation and flushing of mud cakes, and the model is too ideal. Guo Xiaoyang proposed a high-temperature and high-pressure cementing ability evaluation device for the first and second cementing interfaces (Guo Xiaoyang, Zhang Kai, Li Zaoyuan, et al. Device and method for testing the sealing capacity of the first and second interfaces of high-temperature and high-pressure well cementing[P].Sichuan : CN104406910A, 2015-03-11.), although this device can carry out to the cementing second cementing interface, what it adopts is artificial rock core simulation stratum, and there is big difference between its cementing state and the real situation of the downhole second interface; At the same time, the device can measure the first and second cemented interfaces, which may cause the fluid to cross between the two interfaces. For example, the gas at the first interface is measured because the cementation strength of the first interface is much greater than that of the second interface. Phenomena such as the second interface, etc., affect the experimental results, especially the channeling of the second cemented interface has multiple channels, such as the core itself, the cemented surface of the core and the cement sheath, etc., the device cannot distinguish which channel the gas channeling comes from Channel, so there are many unreasonable things in this instrument.

In the current research, some non-permeable metal sheets are used in the simulated formations, so the evaluation of the cementation quality of the second cementing interface has no reference value. There are also artificial cores used to simulate strata, but it does not explain how the artificial core simulates the actual stratum and whether it meets the physical parameters of the on-site stratum. Long, the man-made core used does not conform to the site conditions, the reference value of the simulation results is low, and basically has no actual reference value.

Contents of the invention

In order to overcome the deficiencies described in the background technology, the present invention provides an evaluation device and an experimental method for the cementing quality of the second cementing interface. Mud cakes can be directly used on-site cores or artificial cores. According to the data of the whole rock, clay composition, particle size distribution, permeability, porosity, oil-gas-water saturation and other data of the formation rocks, the artificial cores of the simulated formations are artificially pressed. In addition, the device adopts a core cap treatment for the core, which separates the first interface, the second interface and the core itself from the three channels where gas channeling may occur, and can accurately obtain the pressure and flow rate of the second interface gas channeling.

The technical solution adopted by the present invention to solve its technical problems is:

An evaluation device for the cementing quality of the second interface of well cementing, comprising a kettle body, a core is arranged inside the kettle body, a cement sheath is arranged between the core and the kettle body; There is a gap between them; there is a wool pad at the bottom of the core, and the wool pad is in the middle to fix the core and prevent the cement slurry from flowing into the high-pressure gas pipeline on the lower plug; the outer side of the cement ring and the inner side of the kettle body closely form the first interface gas channel, The outer surface of the core and the inner surface of the cement sheath closely constitute the second interface gas channeling channel.

The core is a real core with a diameter between 25mm and 50mm and a height of 50mm. If there is no core drilled from the actual underground strata, it can be pressed with cuttings, or according to the whole rock, clay composition, particle size distribution, and permeability of the stratum. , porosity, oil-gas-water saturation and other data, and artificially suppress the artificial core of the simulated formation.

The gap allows gas channeling from the second interface to escape, and the hole in the center of the core cap and the pipeline are connected to the permeable gas channel of the core body, so that the gas channeling from the second interface can be separated from the gas permeating through the core itself.

A heating jacket is closely arranged on the outer surface of the kettle body, a thermocouple is arranged inside the heating jacket for heating, and an insulation layer is arranged closely on the outer surface of the heating jacket for heat preservation.

The upper part of the kettle body is connected to the upper end cover, and the lower part of the upper end cover is provided with an upper ceramic gasket and an upper plug. port, core body infiltration gas collection port and second interface gas channeling gas collection port, the sealing ring is used to separate the gas when gas channeling occurs at the first and second interfaces, and the first interface gas channeling gas collection port is used to collect cement The first cemented interface formed by the ring and the inner surface of the kettle is the gas that escapes when gas channeling occurs. The core body infiltration gas collection port is used to collect the gas permeated by the core itself, and the second interface gas channeling gas collection port is used to collect the core and cement. The gas that escapes when gas channeling occurs on the cemented surface of the second interface formed by the ring, in this device, the gas channeling gas permeated through the first interface, the second interface and the core itself are all separated separately, and the occurrence of the second interface can be accurately known. Pressure and flow during gas blow-by.

The lower part of the kettle body is connected to the lower end cover, and the upper surface of the lower end cover is closely arranged with a lower ceramic gasket, a lower head and a lower plug in sequence, and a graphite filler is arranged at the gap between the lower plug and the kettle body, and the graphite filler ensures the sealing performance , the lower ceramic gasket is used for heat insulation, and a high-pressure gas pipeline is arranged in the direction of the central axis of the lower plug, and high-pressure air or high-pressure fluid is input to the device through the high-pressure gas pipeline; there is an air passage between the lower plug and the cement ring, through The high-pressure gas input by the high-pressure gas pipeline flows through the wool pad and the gas channel to the core and the lower part of the cement sheath to simulate downhole gas channeling.

The high-pressure gas pipeline is connected to two pipelines: one is to connect the gas pressure gauge, the gas regulator valve and the nitrogen source through a special one-way valve, and the other is to connect the first hydraulic pressure gauge and the first hydraulic pump through the first control valve; The first pipeline is used to fill the device with nitrogen with a certain pressure to simulate gas channeling to test the bonding quality of each interface; the second pipeline is used to fill the device with a certain pressure of fluid for cleaning Curing pressure builds up inside the unit or during cement sheath formation. The special one-way valve can only be opened when the pressure released by the nitrogen source is greater than the hydraulic pressure in the kettle body, and the fluid can only enter the kettle body and cannot return to the nitrogen source. If the pressure released by the nitrogen source is lower than the hydraulic pressure in the kettle body , the gas released from the nitrogen source cannot pass through the valve.

The first interface gas channeling gas collection port, the core body permeated gas collection port and the second interface gas channeling gas collection port are respectively connected to the first interface gas channeling gas collection bottle, the core body permeated gas gas collection bottle and the second interface gas channeling gas collection port through pipelines. Two-interface gas channeling gas collection cylinder; along the gas flow direction, each pipeline is provided with a back pressure valve, pressure gauge and flow meter in sequence; when gas channeling occurs, the gas escapes upward and escapes from the nearest gas collection port , through the corresponding back pressure valve, the flow rate is recorded by the flow meter and the gas is collected by each gas collection bottle. Since the amount of gas passing through each interface is small, you can observe whether there is gas entering the gas collecting bottle by generating bubbles, and you can know whether each interface is broken down. When gas channeling occurs at the interface, the air pressure can represent the cementation quality of the interface. .

The gas blow-by gas collection port of the first interface is also connected to the second control valve, the third control valve, the second hydraulic pressure gauge and the second hydraulic pump through pipelines, and the gas blow-by gas collection port of the second interface is also connected to the second control valve through pipelines. On the pipeline between the second control valve and the third control valve, it is convenient to input a certain pressure liquid into the device through the gas channeling gas collection port of the first interface and the gas channeling gas collection port of the second interface, and at the same time, the high pressure gas pipeline is connected with the hydraulic pump , a certain pressure liquid can be injected into the lower part of the cement sheath, and the cement sheath can be squeezed up and down (the upper and lower pressures are equal, otherwise the cement sheath may be displaced) to simulate the formation pressure of the downhole cement sheath, as well as its own weight or overlying formation pressure.

Preferably, the thermocouple, pressure gauge, second hydraulic pressure gauge, gas pressure gauge, first hydraulic pressure gauge and flowmeter are respectively electrically connected to a computer, and the data is recorded and analyzed by the computer.

An experimental method of an evaluation device for the cementing quality of the second interface of well cementing, comprising the following steps:

1) Preparation of mud cake: drying the core, putting it into a core vacuum saturation device, vacuuming, saturating the formation drilling fluid in a vacuum environment, forming a mud cake on the outer surface of the core, and simulating the formation of the formation mud cake;

2) Flushing: After the mud cake is formed, the core is put into the device and fixed, and the flushing fluid commonly used in cementing is pumped into the high-pressure gas pipeline, and the gas channeling gas collection port of the first interface and the gas channeling gas of the second interface are collected After a period of time, the flushing fluid is released and replaced with an isolating fluid. After a certain period of circulation according to the experiment, all the liquid in the device is released to simulate the flushing fluid and isolating fluid in the subsequent construction. The effect on the formation interface; the flushing fluid and spacer fluid here are determined according to the specific experimental requirements or downhole conditions; which flushing fluid or spacer fluid to choose;

3) Prepare the cement sheath: take out the rock core, put a core cap on the rock core, put a wool pad in the kettle body, then put the rock core on the wool pad in the kettle body and fix it, and move to the annulus between the rock core and the kettle body After the cement slurry is injected, cover the plug, the upper ceramic gasket and the upper end cover. Under the action of the first hydraulic pump and the second hydraulic pump, the gas channeling gas is collected through the high-pressure gas pipeline and the first interface. The pressure fluid required for cement curing is injected into the gas channeling port of the second interface and the gas channeling gas collection port of the second interface to simulate the pressure of the downhole cement sheath. The pressure fluid can directly use water or neutral hydraulic oil; the pressure fluid passes through the first hydraulic pump Pumped out, flows through the first hydraulic pressure gauge, and the first control valve enters under the cement sheath; the pressure fluid is also pumped out through the second hydraulic pump, flows through the second hydraulic pressure gauge, the third control valve and the gas channeling gas at the second interface The collection port and the second hydraulic pressure gauge, the third control valve, the second control valve and the first interface gas channeling gas collection port enter into the top of the cement sheath; the purpose of injecting pressure fluid: because the downhole cement sheath is affected by the formation pressure, and at the same time its own weight or the pressure of the overlying formation, so in order to simulate this pressure, in this device, the first and second hydraulic pumps are injected into the upper and lower sides of the cement sheath with a certain pressure (the pressure is adjusted according to the formation pressure). Fluid, squeeze the cement sheath up and down (the upper and lower pressures are equal, otherwise the cement sheath may be displaced) to simulate the pressure of the downhole cement sheath; at the same time, turn on the heating belt to heat to the set temperature, according to the experiment and actual needs, in the Curing under certain temperature conditions, the temperature is determined by the stratum temperature simulated by the experiment, and the curing time is determined according to the characteristics of the cement slurry and the simulated stratum environment and other factors, or set according to the specific simulated experimental requirements;

4) The high-pressure gas pipeline is replaced with a special one-way valve, the gas channeling gas collection port of the first interface and the gas channeling gas collection port of the second interface are replaced with a back pressure valve, and the back pressure valve is adjusted until the internal pressure of the kettle body is required for cement maintenance Pressure, because there is pressure fluid inside the kettle body (previously injected to simulate the curing pressure of the cement ring), so the pressure on the back pressure valve, that is, the back pressure valve, is set as the curing pressure, and when gas channeling occurs, the lower high-pressure gas Go to the upper part to increase the pressure of the upper part. At this time, the pressure of the upper part will be greater than the pressure of the back pressure valve, the gas will flow out from the back pressure valve, and the internal pressure of the kettle body will decrease until it is equal to the set cement ring curing pressure value;

5) Introduce high-pressure gas, gradually increase the air pressure, and observe whether there are bubbles in the second interface gas channeling gas collection bottle and the pressure change of the gas barometer. If there are bubbles or a significant change in the gas barometer, it indicates the second cemented interface At this time, the air pressure obtained by the gas barometer is the anti-channeling pressure of the second cemented interface, which can characterize the cementation quality of the second cemented interface.

Preferably, in step 1), the time for drying the core is 45-50h, the time for vacuuming is 6-10h, the vacuum degree in the core vacuum saturation device is not less than 0.1MPa, and the time for saturated formation drilling fluid is 6-10h .

The advantages of the present invention are:

1) the rock core that the present invention adopts is real rock core, and volume is less, overcomes the problem that the demand for rock core is too large, and can form mud cake;

2) The present invention separates three gas channeling passages (the first interface, the second interface, and the core itself) that may occur in the core under pressure, and can accurately obtain the pressure and flow rate of the gas channeling at the second interface to achieve the goal of controlling the gas channeling of the second interface. Accurate characterization of the bonding quality of the two interfaces;

3) The present invention can also change the pressure fluid used for curing the cement into a corrosive fluid, and the device can be used to study the influence of fluid corrosiveness on the anti-channeling ability of the cement sheath;

4) The present invention can simulate the anti-gas channeling experiment of the cement sheath under high temperature and high pressure.

Description of drawings

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

Fig. 2 is a schematic diagram of the structure at the core cap of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

Example 1:

An evaluation device for cementing quality of the second interface of well cementing, comprising a kettle body 10, a rock core 11 is arranged inside the kettle body 10, a cement sheath 12 is arranged between the rock core 11 and the kettle body 10; a core cap 13 is set on the top of the rock core 11, A gap 14 is provided between the lower edge of the core cap 13 and the cement sheath 12; a wool pad 15 is provided at the bottom of the rock core 11; the cement sheath 12 and the kettle body 10 form a first cemented interface 16, and the rock core 11 and the cement sheath 12 form a second cemented interface 17. The gap 14 allows the second interface gas channeling gas to escape, and the center of the core cap 13 has holes and pipelines connected with the core body permeating gas channel, so that the gas channeling through the second interface can be separated from the gas permeating from the core 11 itself.

In order to simulate the influence of formation temperature on the cement sheath 12 bonding strength, a heating jacket 18 is closely arranged on the outer surface of the kettle body 10, a thermocouple is arranged inside the heating jacket 18, and an insulating layer 19 is arranged closely on the outer surface of the heating jacket 18.

The upper part of the kettle body 10 is connected to the upper end cover 20, and the lower part of the upper end cover 20 is provided with an upper ceramic gasket 50 and an upper plug 22, and the upper plug 22 is provided with a sealing ring 23, a first interface gas channeling gas collection port 24, The core body infiltration gas collection port 25 and the second interface gas channeling gas collection port 26; the sealing ring 23 is used to separate the gas when gas channeling occurs at the first and second interfaces, and the first interface gas channeling gas collection port 24 is used for Collect the escaped gas when the first cemented interface 16 formed by the cement sheath 12 and the kettle body 10 undergoes gas channeling. The core body infiltration gas collection port 25 is used to collect the gas permeated by the core itself. The second interface gas channeling gas collection port 26 It is used to collect the escaped gas when the second cemented interface 17 formed by the core 11 and the cement sheath 12 undergoes gas channeling. In this device, the gas permeated by the first interface 16, the second interface 17 and the core 11 itself are all separated separately The pressure and flow rate when gas channeling occurs at the second interface can be accurately known.

The lower part of the kettle body 10 is connected to the lower end cover 27, and the upper surface of the lower end cover 27 is closely arranged with a lower ceramic gasket 28, a lower sealing head 29 and a lower plug 30, and the gap between the lower plug 30 and the kettle body 10 is provided with a Graphite packing 31, graphite packing 31 guarantees the sealing performance, the lower ceramic gasket 28 is used for heat insulation, and the central axis direction of the lower plug 30 is provided with a high-pressure gas pipeline 32, and high-pressure air or high-pressure fluid is input to the device through the high-pressure gas pipeline 32; A gas passage 33 is provided between the plug 30 and the cement sheath 12, and the high-pressure gas input through the high-pressure gas pipeline 32 is evenly distributed to the lower part of the core 11 and the cement sheath 12 through the wool pad 15 and the gas passage 33, simulating downhole gas channeling condition.

The high-pressure gas pipeline 32 is connected to two pipelines: one is to connect the gas pressure gauge 35, the gas regulator valve 36 and the nitrogen source 37 through a special one-way valve 34; the other is to connect the first hydraulic pressure gauge through the first control valve 38 39 and the first hydraulic pump 40; the first pipeline is used to charge nitrogen with a certain pressure to the device, and is used to test the bonding quality of each interface; the second pipeline is used to charge the device with a certain pressure. The pressurized fluid is used for cleaning the interior of the device and for maintenance during the formation of the cement sheath 12 .

The first interface gas channeling gas collection port 24, the core body infiltration gas collection port 25 and the second interface gas channeling gas collection port 26 are respectively connected to the first interface gas channeling gas collection bottle 41 and the core body infiltration gas collection port 26 through pipelines. Gas cylinder 42 and second interface gas channeling gas collecting bottle 43; along the gas flow direction, each pipeline is provided with a back pressure valve 44, a pressure gauge 45 and a flow meter 46 in sequence; And escape from the nearest gas collection port, pass through the corresponding back pressure valve 44, record the flow size through the flow meter 46 and collect the gas by each gas collection bottle.

In order to facilitate the input of a certain pressure liquid into the device through the first interface gas channeling gas collection port 24 and the second interface gas channeling gas collection port 26, the first interface gas channeling gas collection port 24 is also connected to the second interface gas channeling port through a pipeline. The control valve 47, the third control valve 48, the second hydraulic pressure gauge 49 and the second hydraulic pump 51, and the second interface blow-by gas collection port 26 are also connected between the second control valve 47 and the third control valve 48 through pipelines on the pipeline.

In order to improve the characterization accuracy, the present invention uses a computer to record and analyze data, and the thermocouple, pressure gauge 45, second hydraulic pressure gauge 49, gas pressure gauge 35, first hydraulic pressure gauge 39 and flowmeter 46 are electrically connected to the computer respectively.

Example 2:

Adopt the experimental method of the evaluation device of a kind of cementing second interface cementing quality described in embodiment 1, comprise the steps:

1) Preparation of mud cake: drying the core 11, putting it into a core vacuum saturation device, vacuuming, saturating the formation drilling fluid in a vacuum environment, and simulating the formation of formation mud cake on the outer surface of the core;

2) Flushing: After the mud cake is formed, the rock core 11 is put into the device and fixed, and the flushing fluid commonly used in cementing is pumped in from the high-pressure gas pipeline 32, and the gas channeling from the first interface to the gas collection port 24, the second interface gas The channeling gas collection port 26 and the core body infiltration gas collection port 25 flow out, and last for a period of time, then release the flushing fluid and replace it with the spacer fluid, and release all the liquid in the device after circulating for a certain period of time according to the experimental requirements, simulating the subsequent construction The effect of flushing fluid and spacer fluid on the formation interface;

3) Prepare the cement sheath 12: take out the rock core 11, put a rock core cap 13 on the rock core 11, put a wool pad 15 in the kettle body 10, then put the rock core 11 into the wool pad 15 in the kettle body 10 and fix it, Inject cement slurry into the annular space between the rock core 11 and the kettle body 10 (the height of the cement slurry just submerges the sealing ring by 2 to 4 cm), and after the injection of the cement slurry is completed, cover the plug 20, the upper ceramic gasket 50 and the upper end cover 22 , under the action of the first hydraulic pump 40 and the second hydraulic pump 51, through the high-pressure gas pipeline 32, the first interface gas channeling gas collection port 24 and the second interface gas channeling gas collection port 26, the pressure required for cement curing Pressurized fluid, simultaneously turn on the heating belt 18 to heat to the set temperature, and maintain under certain temperature conditions according to the experiment and actual needs;

4) The high-pressure gas pipeline 32 is replaced with a special one-way valve 34, the first interface gas channeling gas collection port 24 and the second interface gas channeling gas collection port 26 are replaced with a back pressure valve 44, and the back pressure valve 44 is adjusted until the kettle body 10 The internal pressure is the pressure required for cement curing;

5) Feed high-pressure gas, gradually increase the air pressure, observe whether there are bubbles in the second interface gas channeling gas collecting bottle 43 and the pressure change of the gas barometer, if there are bubbles or significant changes in the gas barometer 35, it indicates that the second interface The cemented interface has channeled through. At this time, the air pressure obtained by the gas pressure gauge 35 is the anti-channeling pressure of the second cemented interface, which can represent the cemented quality of the second cemented interface.

Wherein, in step 1), the time for drying the core is 48 hours, the time for vacuuming is 24 hours, the vacuum degree in the core vacuum saturation device is not less than 0.1 MPa, and the time for saturating the formation drilling fluid is 24 hours.

Finally, it should be noted that: obviously, the above-mentioned embodiments are only examples for clearly illustrating the present invention, rather than limiting the implementation. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. However, obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (4)

1. a kind of evaluating apparatus for second contact surface bonding quality of cementing the well, which is characterized in that including autoclave body, autoclave body is internally provided with rock The heart is provided with cement sheath between rock core and autoclave body；It is cased with rock core cap at the top of rock core, is provided between rock core cap lower edge and cement sheath Gap；Rock core bottom is provided with wool pad；Cement sheath lateral surface and autoclave body medial surface closely form the first interface has channeling channel, rock Facies lateralis cordis and cement sheath medial surface closely form second contact surface has channeling channel；

The autoclave body lateral surface is closely provided with heating mantle, and heating mantle is internally provided with thermocouple, and heating mantle lateral surface is close It is provided with insulating layer；

Upper end cover is partially connected on the autoclave body, upper end cover lower part is provided with upper plug head and upper ceramic washer, sets on upper plug head It is equipped with sealing ring, the first interface has channeling gas collection mouth, rock core body infiltration gas collection mouth and second contact surface has channeling gas collection Mouthful；

Partially connect lower cover under the autoclave body, lower end cap upper surface be successively closely provided with lower ceramic washer, lower head and The gap location of lower end cap, lower end cap and autoclave body is provided with graphite packing, and lower end cap central axes direction is provided with high-pressure gas pipelines, Air drain was provided between lower end cap and cement sheath；

The high-pressure gas pipelines connect two pipelines：First is that connecting gas gauge, gas pressure stabilizing by special check valve Valve and source nitrogen, second is that connecting the first hydraulic gage and the first hydraulic pump by the first control valve；

First interface has channeling gas collection mouth, rock core body infiltration gas collection mouth and the second contact surface has channeling gas collection mouth The first interface has channeling gas collection bottle is connected by pipeline respectively, rock core body permeates gas collection bottle and second contact surface has channeling gas Gas bottle；Along gas flow direction, back-pressure valve, pressure gauge and flowmeter are disposed on each pipeline；

The first interface has channeling gas collection mouth also connects the second control valve, third control valve, second hydraulic by pipeline Pressure gauge and the second hydraulic pump, second contact surface has channeling gas collection mouth also pass through pipeline and are connected to the second control valve and third control On pipeline between valve.

2. a kind of evaluating apparatus of second contact surface bonding quality of cementing the well as described in claim 1, which is characterized in that the heat Galvanic couple, pressure gauge, the second hydraulic gage, gas gauge, the first hydraulic gage and flowmeter are electrically connected computer.

3. a kind of experimental method of the evaluating apparatus using well cementation second contact surface bonding quality as claimed in claim 1 or 2, It is characterized in that, described method includes following steps：

1) mud cake is prepared：Rock core is dried, is put into rock core vacuum saturation device, vacuumize process, is satisfied in the case where vacuumizing environment With strata drilling liquid, in the formation of core outside surface simulated formation mud cake；

2) it rinses：After mud cake is formed, rock core is put into the device and is fixed, it is common to be pumped into well cementation by high-pressure gas pipelines Flushing liquor permeates gas collection by the first interface has channeling gas collection mouth, second contact surface has channeling gas collection mouth and rock core body Mouth outflow, and continue for some time, flushing liquor is bled off later, is changed insulating liquid into and is needed to recycle after a certain period of time according to experiment by dress Liquid in setting discharges entirely, simulates the effect of flushing liquor and insulating liquid to bed boundary in subsequent construction；

3) cement sheath is prepared：Removal of core covers rock core cap on rock core, and wool pad is put into autoclave body, is later put into rock core On wool pad in autoclave body and fix, to the annular space between rock core and autoclave body at inject cement slurry, cement slurry to be implanted finishes Afterwards, plug, upper ceramic washer and upper end cover are covered and passes through high pressure gas under the action of the first hydraulic pump and the second hydraulic pump The pressure of required pressure when pipeline, the first interface has channeling gas collection mouth and second contact surface has channeling gas collection mouth injection cement conservation Force flow body opens simultaneously heating tape and is heated to set temperature, according to experiment and actual needs, supports in a certain temperature conditions Protect appropriate time；

4) the special check valve of high-pressure gas pipelines changing-over, the first interface has channeling gas collection mouth and second contact surface has channeling gas collection Mouthful changing-over back-pressure valve adjusts back-pressure valve, sets the pressure of back-pressure valve as autoclave body internal pressure, i.e. pressure needed for cement conservation；

5) it is passed through high pressure gas by high-pressure gas pipelines, is gradually increased air pressure, whether is observation second contact surface has channeling gas collection bottle There is bubble to generate and the barometric pressure change of gas, if there is bubble or significant changes occurs in gas atmosphere table, shows the Alter logical at two cementation interfaces, air pressure obtained by gas atmosphere table at this time is that the anti-of the second cementation interface alters pressure size, can be characterized The bonding quality of second cementation interface.

4. experimental method as claimed in claim 3, which is characterized in that in step 1）In, the time of rock core drying is 45-50h, The time vacuumized is 6-10h, and vacuum degree is not less than 0.1MPa in rock core vacuum saturation device, is saturated the time of strata drilling liquid For 6-10h.