CN103018147A - Method for measuring total porosity of shale - Google Patents

Abstract

The invention discloses a method for measuring the total porosity of shale, which is applied to laboratories for oil exploration, geological exploration and mineral exploration to perform a shale measurement. The method is characterized by comprising the following steps of: measuring the apparent volume of a shale sample; crushing the same sample used aforementioned to 100-200 meshes; performing drying treatment for 24-48 hours at 60-80 DEG C; performing cyclic crushing on the shale sample into fine particles which are 100-1000 nm in diameter by an auxiliary liquid, and measuring the volume of the consumed auxiliary liquid; and measuring the volume of the mixed liquid of the auxiliary liquid and the shale sample after the cyclic crushing, and calculating to obtain the total porosity of the shale sample. The method has the effects of being capable of measuring the total porosity of shale and high in measurement accuracy.

Description

A method for measuring total porosity of shale

technical field

The invention relates to the technical fields of petroleum, geology, and mining exploration and development, in particular to a method for measuring mud shale in a laboratory, which is a method for measuring the total porosity of mud shale.

Background technique

In the process of exploration and development of shale oil and gas, total porosity is one of the key parameters for calculating shale oil and shale gas resources and making development plans. The total porosity of shale oil and shale gas reservoirs directly affects the resources of shale oil and shale gas, and is used to evaluate the production cycle of shale oil and shale gas wells. The source rock and reservoir of shale oil and shale gas are the same set of mud shale, and a considerable part of the pores in mud shale are disconnected, that is, "dead pores". The oil and gas stored in these disconnected pores can be exploited after fracturing, so it is necessary to measure the total porosity of shale oil and gas reservoirs in order to calculate the amount of shale oil and gas resources, and The production cycle of shale oil and gas wells is evaluated. At present, the basic methods for measuring rock pores include: gas method and liquid method. The gas method is to put the rock sample into a closed device, fill the device with high-pressure gas, and calculate the rock porosity according to Boyle's law; the liquid method is to vacuumize the rock sample and saturate it with kerosene (or saturated alcohol), and use the rock sample to saturate The porosity was calculated from the weight difference before and after kerosene. However, these methods can only measure the interconnected pores in the rock, but cannot measure the size of the disconnected pores, that is, only the effective porosity can be measured, and the total porosity cannot be measured. Therefore, using the basic method of measuring rock pores to evaluate shale oil and gas reservoirs will cause the porosity value to be too small, which cannot truly reflect the total porosity of shale reservoirs, thereby affecting the calculation of shale oil and gas resources and the calculation of shale oil and gas wells. production cycle assessment.

Those skilled in the art commonly use the immersion method to measure the apparent volume of shale samples. The immersion method can be used to measure the volume of irregularly shaped samples that are neither soluble nor absorbent in water. Submerge the entire sample to be tested in water, and the volume difference between the two readings is the apparent volume of the sample. For water-absorbing shale samples, fine powder (such as silt, flour, etc.) can be used instead of water to measure its apparent volume by immersion method.

Through patent retrieval, Chinese patent, 201110155601 published invention patent application "shale porosity measurement method" (application publication number: CN 102252948A) has a major defect in principle: it is considered that the density of mud shale before and after crushing Similarly, use the ratio of the mass M ₁ of the crushed sample to the density ρ _b before crushing to calculate the volume before crushing. During the pulverization process of mud shale (crushed until the particle size is smaller than the smallest non-connected pores of the sample, which is equivalent to the particle size of the nanometer level), a large amount of heat will be generated, so that fluids such as water and oil in the mud shale will become gaseous due to heating and from the pulverized sample In this way, the density of the shale samples before and after crushing changes. The calculated shale porosity in this way is biased. For this reason, the present invention uses a closed device to use circulating fluid (which can play the role of cooling and circulation) to carry out circular crushing of mud shale samples, and obtains the porosity of mud shale through the volume change before and after crushing. precision.

Contents of the invention

The purpose of the present invention is to provide a method for measuring the total porosity of mud shale, so as to realize the accurate measurement of the total porosity of mud shale. The invention overcomes the deficiency that the existing technologies and methods are difficult to accurately measure the total porosity of mud shale. Another object of the present invention is to provide a device for measuring the total porosity of mud shale, which is used to realize the method for measuring the total porosity of mud shale.

The technical scheme adopted in the present invention is: the method for measuring the total porosity of mud shale, it is characterized in that:

Step 1: Measure the apparent volume of the shale sample with the immersion method or a vernier caliper, and record the apparent volume V ₁ , and the unit of the apparent volume is cm ³ ;

Step 2: crush the same shale sample above to 100-200 mesh;

Step 3: drying the pulverized mud shale sample at a temperature of 60-80°C for 24-48 hours to remove water and hydrocarbons in the mud shale sample;

Step 4: Mix the above-mentioned dried shale samples with the auxiliary liquid for cyclic crushing, and cyclically crush the shale samples to fine particles with a diameter of 100-1000 nm; measure and consume the volume V ₂ of the auxiliary liquid, and consume the auxiliary liquid The unit of volume _V2 is mL;

Step 5: Measure the total volume V ₃ of the mixed liquid of the auxiliary liquid and the fine particles of the shale sample, and the unit of measuring the total volume V ₃ of the mixed liquid of the auxiliary liquid and the fine particles of the shale sample is mL;

Step 6: Calculate the total porosity Φ of the shale sample according to the following formula, and the unit of the total porosity Φ of the shale sample is %:

φ=(V ₁ -(V ₃ -V ₂ ))/V ₁ ×100%

When the shape of the mud shale sample is a regular cylinder, use a vernier caliper to measure the diameter and height of the mud shale sample, and then calculate the apparent volume of the mud shale sample; when the shape of the mud shale sample is non-cylindrical, use the immersion method to measure the mud shale The apparent volume of the rock sample.

The auxiliary fluid can be alcohol, kerosene, distilled water, etc.

The auxiliary fluid volume V ₂ is metered and consumed. Before adding the auxiliary liquid to the circulating crushing device, use a high-precision measuring cylinder (patent publication number of high-precision measuring cylinder: CN202420600U) to measure the volume of the poured auxiliary liquid. This volume is the volume V ₂ of the auxiliary liquid consumed, and the measured volume is accurate to 0.01mL.

Measure the total volume V ₃ of the mixed liquid of the auxiliary liquid and the fine particles of the shale sample. After the circulation crushing is completed, the mixed liquid of the auxiliary fluid and the fine particles of the shale sample is discharged from the circulating crushing device, and the volume V ₃ of the mixed liquid is measured with a high-precision measuring cylinder (patent publication number of high-precision measuring cylinder: CN202420600U), and the measurement accuracy is to 0.01 mL.

The circulation crushing is carried out in a circulation crushing device. The circulating crushing device includes a first valve (1), a second valve (2), a third valve (3), an upper U-shaped glass tube A, a lower U-shaped glass tube D, a small pulverizer (B) and a small pump (C). The U-shaped openings of the upper U-shaped glass tube A and the lower U-shaped glass tube D are opposite to each other; one port of the upper U-shaped glass tube (A) is connected with the discharge port of the small pulverizer (B) through a rubber hose, and the small pulverizer The feeding port of the machine (B) is connected with one port of the lower U-shaped glass tube D through a rubber hose; the other port of the upper U-shaped glass tube (A) is connected with the feeding port of the small pump C through a rubber hose, The discharge port of the small pump C is connected to the other port of the lower U-shaped glass tube D through a rubber hose; the top of the upper U-shaped glass tube (A) is connected to the feed pipe port, and the lower part of the feed pipe port has a second A valve 1 has a second valve 2 on the upper U-shaped glass tube A; a discharge nozzle is connected to the bottom of the lower U-shaped glass tube D, and a third valve 3 is connected to the discharge nozzle.

The use of circulation crushing device. Before circulating the pulverized shale sample, it is necessary to open the first valve (1), the second valve (2) and the third valve (3), and pour the auxiliary liquid from the feeding nozzle of the upper U-shaped glass tube (A) Wetting the circulating crushing device, the auxiliary liquid consumed for wetting is not included in the consumed auxiliary liquid volume V ₂ . Close the second valve (2) and the third valve (3) during the circulation crushing process, and pour the dried and processed mud shale sample and part of the auxiliary liquid from the upper feeding nozzle of the upper U-shaped glass tube (A), Open the second valve (2) and continue to pour the auxiliary liquid from the upper feed port of the upper U-shaped glass tube (A), and stop adding the auxiliary liquid when the auxiliary liquid is almost full of the upper U-shaped glass tube (A) and the lower U-shaped glass tube D liquid, close the first valve (1); turn on the small pulverizer (B) and the small electric pump (C), carry out circular pulverization on the mud shale sample and adjust the pulverization degree of the small pulverizer (B). The mud shale sample is crushed into fine particles with a diameter of 100-1000nm; the small pulverizer (B) and the small electric pump (C) are closed, the first valve (1) and the third valve (3) are opened, and the U-shaped glass Use a container to collect the mixture of auxiliary liquid and shale fine particles under the outlet port at the bottom of pipe D, and pour the auxiliary liquid into the feeding pipe port at the upper end of the upper U-shaped glass tube (A) to clean the circulating crushing device and clean it. The auxiliary liquid of the residual mud shale fine particles in the circulating crushing device also flows out from the discharge nozzle at the bottom of the lower U-shaped glass tube D and is collected together with the upper container, and finally measures the volume of auxiliary liquid V ₂ consumed except for the wetting circulating device .

Beneficial effects of the present invention: the method for measuring the total porosity of mud shale in the present invention realizes the accurate measurement of the total porosity of mud shale, and the measurement method is low in cost and easy to operate, and the total porosity of the measured mud shale reservoir is Porosity is an important evaluation parameter necessary for the exploration and development of shale oil and gas.

Description of drawings

Fig. 1 is a schematic flow chart of the method for measuring the total porosity of mud shale according to the present invention.

Fig. 2 is a schematic diagram of the structure of a circulating crushing device.

In the figure, 1-first valve, 2-second valve, 3-third valve, A-upper U-shaped glass tube, B-small pulverizer, C-small pump, D-lower U-shaped glass tube.

Detailed ways

Embodiment 1: Taking the method of measuring the total porosity of mud shale once as an example, the present invention is further described in detail.

See Figure 2. The circulating crushing device includes a first valve (1), a second valve (2), a third valve (3), an upper U-shaped glass tube A, a lower U-shaped glass tube D, a small pulverizer (B) and a small pump (C ). The model of small pulverizer B is ZM 200; the model of small pump C is WT3000-1JA.

The inner diameter of the upper U-shaped glass tube A and the lower U-shaped glass tube D is 40mm. The U-shaped openings of the upper U-shaped glass tube A and the lower U-shaped glass tube D are opposite to each other; one port of the upper U-shaped glass tube (A) is connected with the discharge port of the small pulverizer (B) through a rubber hose, and the small pulverizer The feeding port of the machine (B) is connected with one port of the lower U-shaped glass tube D through a rubber hose; the other port of the upper U-shaped glass tube (A) is connected with the feeding port of the small pump C through a rubber hose, The discharge port of the small pump C is connected to the other port of the lower U-shaped glass tube D through a rubber hose; the top of the upper U-shaped glass tube (A) is connected to the feeding nozzle, and the lower part of the feeding nozzle has a second A valve 1 has a second valve 2 on the upper U-shaped glass tube A; a discharge nozzle is connected to the bottom of the lower U-shaped glass tube D, and a third valve 3 is connected to the discharge nozzle. The capacity of the circulating crushing device is 2500mL.

See Figure 1. Methods for measuring the total porosity of shale:

Step 1: Measure the apparent volume of the mud shale sample by immersion method, the apparent volume of the mud shale sample is 25.14 cubic centimeters. Record apparent volume V ₁ 25.14 mm3;

Step 2: pulverize the above-mentioned shale sample for measuring the apparent volume to 150 mesh;

Step 3: drying the pulverized mud shale sample at a temperature of 70° C. for 48 hours to remove water and hydrocarbons in the mud shale sample;

Step 4: Mix the dried shale sample with the auxiliary liquid for cyclic crushing, and cyclically crush the shale sample to fine particles with a diameter of 800nm; measure and consume the volume V ₂ of the auxiliary liquid, and consume the volume V of the auxiliary liquid ₂ is 1834.25 ml;

Step 5: Measure the total volume V ₃ of the mixed liquid of the auxiliary fluid and the fine particles of the shale sample; measure the total volume V ₃ of the mixed liquid of the auxiliary liquid and the fine particles of the shale sample to be 1850.32 milliliters;

Step 6: Calculate the total porosity Φ of the shale sample according to the following formula, and the unit of the total porosity Φ of the shale sample is %:

φ=(V ₁ -(V ₃ -V ₂ ))/V ₁ ×100%

Finally, it is calculated that the total porosity Φ of the shale samples obtained in this test is 3.61%

Kerosene used as auxiliary fluid.

The auxiliary fluid volume V ₂ is metered and consumed. Before adding the auxiliary liquid to the circulating crushing device, use a high-precision measuring cylinder (patent publication number of high-precision measuring cylinder: CN202420600U) to measure the volume of the poured auxiliary liquid. This volume is the volume V ₂ of the auxiliary liquid consumed, and the measured volume is accurate to 0.01mL.

Measure the total volume V ₃ of the mixed liquid of the auxiliary liquid and the fine particles of the shale sample. After the circulation crushing is completed, the mixed liquid of the auxiliary fluid and the fine particles of the shale sample is discharged from the circulating crushing device, and the volume V ₃ of the mixed liquid is measured with a high-precision measuring cylinder (patent publication number of high-precision measuring cylinder: CN202420600U), and the measurement accuracy is to 0.01 mL.

The circulation crushing is carried out in a circulation crushing device.

Claims (2)

1. A method for measuring total porosity of shale, characterized in that: Step 1: Measure the apparent volume of the shale sample with the immersion method or a vernier caliper, record the apparent volume V ₁ , and the unit of the apparent volume is cm ³ . Step 2: crush the same shale sample above to 100-200 mesh; Step 3: drying the pulverized mud shale sample at a temperature of 60-80°C for 24-48 hours to remove water and hydrocarbons in the mud shale sample; Step 4: Mix the above-mentioned dried shale samples with the auxiliary liquid for cyclic crushing, and cyclically crush the shale samples to fine particles with a diameter of 100-1000 nm; measure and consume the volume V ₂ of the auxiliary liquid, and consume the auxiliary liquid The unit of volume _V2 is mL; Step 5: Measure the total volume V ₃ of the mixed liquid of the auxiliary fluid and the fine particles of the shale sample. The unit for measuring the total volume V ₃ of the mixed liquid of the auxiliary fluid and the fine particles of the shale sample is mL. Step 6: Calculate the total porosity Φ of the shale sample according to the following formula, and the unit of the total porosity Φ of the shale sample is %: φ=(V ₁ -(V ₃ -V ₂ ))/V ₁ ×100% When the shape of the mud shale sample is a regular cylinder, use a vernier caliper to measure the diameter and height of the mud shale sample, and then calculate the apparent volume of the mud shale sample; when the shape of the mud shale sample is irregular, use the immersion method to measure the mud shale sample the apparent volume. The auxiliary fluid can be alcohol, kerosene, distilled water, etc. The auxiliary fluid volume V ₂ is metered and consumed. Before adding the auxiliary liquid into the circulating crushing device, use a high-precision measuring cylinder to measure the volume of the auxiliary liquid poured in. This volume is the volume V ₂ of the auxiliary liquid consumed, and the measured volume is accurate to 0.01mL. Measure the total volume V ₃ of the mixed liquid of the auxiliary liquid and the fine particles of the shale sample. After the circulation crushing is completed, the mixed liquid of the auxiliary liquid and the fine particles of the shale sample is discharged from the circulating crushing device, and the volume V ₃ of the mixed liquid is measured with a high-precision measuring cylinder, and the measurement accuracy reaches 0.01 mL. 2. The method for measuring the total porosity of mud shale according to claim 1, characterized in that: said circulation crushing is carried out in a circulation crushing device. The circulating crushing device includes a first valve (1), a second valve (2), a third valve (3), an upper U-shaped glass tube A, a lower U-shaped glass tube D, a small pulverizer (B) and a small pump (C), the upper U-shaped glass tube (A) is opposite to the U-shaped mouth of the lower U-shaped glass tube D; one port of the upper U-shaped glass tube (A) is connected to the discharge port of the small pulverizer (B) through rubber The hose is connected, the feed port of the small pulverizer (B) is connected with one port of the lower U-shaped glass tube D through a rubber hose; the other port of the upper U-shaped glass tube (A) is connected with the feed port of the small pump C Connected by a rubber hose, the discharge port of the small pump C is connected with the other port of the lower U-shaped glass tube D through a rubber hose; the top of the upper U-shaped glass tube (A) is connected with a feed nozzle, and the feed There is a first valve 1 on the lower part of the nozzle, and a second valve 2 on the upper U-shaped glass tube A; a discharge nozzle is connected to the bottom of the lower U-shaped glass tube D, and a third valve 3 is connected to the discharge nozzle. .

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