SY/T 5343-1994 Method for determining the amount of filtrate intrusion into core
Some standard content:
Petroleum and Natural Gas Industry Standard of the People's Republic of China SY/T 5343-94
Method for determination of the amount of filtrate intrusion into the core
Published on January 18, 1995
China National Petroleum Corporation
Implementation on July 1, 1995
1 Subject content and scope of application
Method for determination of the amount of filtrate intrusion into the core of the Petroleum and Natural Gas Industry Standard of the People's Republic of China
Replaces SYT5343-88
This standard specifies the instruments and equipment required for determination of the amount of drilling fluid filtrate intrusion into the core using ammonium thiocyanate as a tracer: materials, reagents, and determination methods and procedures.
This standard is applicable to sandstone oil layers that do not contain thiocyanate cyanide, and when using water-based drilling fluid for large-diameter or closed drilling coring, the amount of drilling fluid filtrate intrusion into the core is determined to check the coring quality. 2 Principle of determination
Add a certain amount of ammonium thiocyanate as a tracer in the foundation drilling. When coring, if the drilling fluid filtrate invades the core, the ammonium thiocyanate dissolved in the filtrate will also enter. By measuring the content of ammonium thiocyanate in the core and the concentration of ammonium thiocyanate in the drilling filter, the degree of invasion of the drilling fluid filtrate into the core can be determined. 3 Preparation work before coring and sampling requirements
3.1 Preparation work before coring
3.1.1 Before coring, place a 21m2 dosing tank next to the channel of circulating drilling fluid, add ammonium thiocyanate (the amount added is calculated based on 1000g of ammonium thiocyanate per 1m2 of drilling fluid), add water (about 2m2) and stir continuously to dissolve it completely. 3.1.2 During circulating drilling: open the valve to slowly flow the ammonium thiocyanate solution into the drilling fluid line. The flow rate should be controlled to make the entire drilling fluid circulate for one cycle. Then, during the circulating drilling fluid, take samples to measure the tracer concentration. Ammonium thiocyanate can also be directly added to the tank containing drilling fluid and used after stirring evenly. 3.2 Sampling requirements
3.2.1 When circulating drilling fluid before coring, the concentration of ammonium thiocyanate should be checked first to make it within 100012001m/L. When the concentration is lower than 800mlg/L: add ammonium thiocyanate and repeat the operation of 3,1.2. 3.2.2 During coring, 200 mL of drilling fluid should be collected at each of the three stages: circulating drilling fluid, starting coring, and ending coring. After mixing the three samples in equal volumes, use them as representative samples of drilling fluid for coring in this barrel. The sampling time and coring barrel number should be noted. 3.2.3 Requirements for core extraction
a. After the core barrel is pulled out of the ground, the cores should be taken immediately, and the order of the cores should not be reversed;. Use clean cotton yarn to remove the sealing fluid or drilling fluid on the cores. It is forbidden to use any fluid for washing to prevent core contamination. c. Place the cores in order, align the cut ends, accurately measure the length of the cores, and mark half a meter or a whole meter. 3.2.4 Sampling requirements:
a. Rock samples should be selected according to the sampling plan: the density is generally 8-10 pieces per meter. The sampling density of the core section with little change in oil occurrence and rock sample can be reduced: on the contrary, the sampling density can be increased. b. When sampling, the sampling well number, core tube number, rock sample number and sampling time should be filled in; c. When taking rock samples, drilling fluid and sealing fluid should be prevented from contaminating the core surface. Take 20-30g of rock sample at the center of the core close to the saturation sample.
d. When taking rock samples, the filtrate or drilling fluid sample of the drilling fluid in Article 3.2.2 of this core sampling should be taken at the same time. China National Petroleum Corporation approved on January 18, 1995 and implemented on July 1, 1995.
4 Determination method
4.1 Iron salt colorimetry
4.1.1 Principle
SY/ T $343-94
Ammonium thiocyanate can react with trivalent iron ions in acidic medium to form a blood red (orange red at low concentrations) complex, the color intensity of which is proportional to the concentration of ammonium thiocyanate. This can be determined by colorimetry, and the reaction equation is as follows: 4SCN- + Fe3+→ [Fe(SCN)]
4.1.2 Instruments and reagents
Blood red
Analytical pure reagents, deionized water or water of equivalent purity that meet national or industry standards are used during analysis. Pneumatic drilling fluid water loss meter (or similar products); balance: sensitivity 0.1g: 101mg each one: b.
Qualitative medium-speed (or slow) filter paper: medium = licm; spectrophotometer: 72 type or similar products: d.www.bzxz.net
Oscillator:
Beaker: 50mL;
Colorimetric tube: 10, 25mL with colorimetric tube rack: Wide-mouth bottle: 60mL;
Volume flask: 25, 500mL;
kMortar:
Ammonium thiocyanate;
Ammonium ferric sulfate:
Nitric acid;
pAnhydrous aluminum chloride (or aluminum nitrate, or potassium aluminum sulfate). 4.1.3 Preparation of solution
4.1.3.1 Ammonium thiocyanate standard solution
Weigh 0.50000g of analytically pure ammonium thiocyanate and put it into a beaker. Dissolve it with deionized water and transfer it to a 500mL volumetric flask. Dilute to the mark and shake well. The concentration of this solution is 1.0m/L. Pipette 10.00mL of the above solution and put it into a 500mL volumetric flask. Dilute to the mark with deionized water and shake well. The concentration of this solution is 20/mL
4.1.3.2 0.2g/L aluminum chloride soaking solution (2g/L potassium aluminum sulfate or aluminum nitrate solution can also be used) Weigh 0.20g of anhydrous aluminum chloride, or 2.0g of potassium aluminum sulfate or 2.0g of aluminum nitrate, put it in a beaker, dissolve it with deionized water and dilute to 1000mL (depending on the number of cores taken, the amount can also be prepared in one go), and store it in a bottle for later use. 4.1.3.3 2.5g/L ammonium ferric sulfate solution Weigh 2.50g of analytically pure ammonium ferric sulfate and place it in a beaker. Dissolve it in 100mL of deionized water and add 0.51mL of nitric acid (or 0.2mL of sulfuric acid).
4.1.3.4 Nitric acid solution (1+3)
Weigh 50mL of concentrated nitric acid, add it to 150mL of deionized water and mix well for later use. 4.1.4 Preparation of ammonium thiocyanate standard series and drawing of standard curve 4.1.4.1 Take 0.00, 1.00, 2.00, 3.00, 4.00, 5.00mL of 20g/mL ammonium thiocyanate standard solution respectively and place them in 25mL colorimetric tubes. Dilute to about 10mL with deionized waterSY/T5343-94
4.1.4.2 Add 1.00mL of 1+3 nitric acid solution and 4.00mL of 25g/L ammonium ferric sulfate solution to the colorimetric tubes in 4.1 and 4.1 respectively, dilute to 25mL mark with deionized water and shake, and place for 15min. 4.1.4.3 Carry out colorimetric determination at a wavelength of 455nm (or use a purple filter), and the determination time shall not exceed 40min4.1.4.4 Draw a standard curve based on the measured optical density value and the content of ammonium thiocyanate. 4.1.5 Analysis of drilling fluid filtrate
4.1.5.1 Analysis steps:
Put the drilling fluid in 3.2.2 into a pneumatic drilling fluid water loss meter with filter paper in place to squeeze out the filtrate b. Pipette 1.00mL of the filtrate into a 25mL volumetric flask, dilute to the mark with deionized water, shake and then pipette 2.50mL of the diluted filtrate into three 25mL colorimetric tubes (two of which are sample tubes and the other is a blank tube), and dilute to 10mL with deionized water;
CAdd 1.00mL of 1+3 nitric acid solution and 4.00mL of 25g/L ammonium ferric sulfate solution to each sample tube; add 1.00mL of 1+3 nitric acid solution to the blank tube. Dilute the sample tube and blank tube to the scale with deionized water, shake and let stand for 15 minutes. Perform colorimetric determination at a wavelength of 455n11 (or purple filter) with the blank sample as reference. The determination conditions are the same as those in 4.1.4.3. Then find the content of ammonium thiocyanate on the standard curve. 4.1.5.2 Calculation
The content of ammonium thiocyanate in the drilling fluid filtrate is calculated according to formula (1). 10
In the formula:
Ammonium thiocyanate concentration in drilling fluid: mg/mL; Ammonium thiocyanate content found from the standard curve. Absorb the volume of drilling fluid filtrate. mL;
Absorb the volume of diluted filtrate, mL.
4.1.6 Analysis of rock samples
Analysis steps:
Crush all rock samples to disperse the sand particles and mix them; b. Weigh 15.00g of each rock sample and put it into a numbered 60mL wide-mouth bottle, add 25mL of the soaking solution in 4.1.3.2, and cover the bottle stopper;
Put the sample bottle on an oscillator and shake it for 30 minutes, then take it out and let it stand for 5 to 10 minutes. Use qualitative medium-speed or slow filter paper to filter the soaking solution into a dry beaker;
d. Take the filtered 4.1.6.10mL of each filtrate from 1(c) is placed in a series of 25mL colorimetric tubes. Occasionally, 10mL of the filtered solution from 4.1.3.2 is taken and placed in a colorimetric tube as a blank sample. 1.00mL of 1+3 nitric acid solution and 4.00mL of 25g/L ammonium ferric sulfate solution are added to the colorimetric tubes of 4.1.6.1(d), respectively. Dilute to the scale with deionized water, shake and let stand for 15min. Use the blank sample as a reference. The colorimetric conditions are the same as those of 4.1.4.3: f. According to the measured optical density value, find the ammonium thiocyanate content on the standard curve. 4.1.6.2 Calculation:
The ammonium thiocyanate content in the rock sample is calculated according to formula (2). a.
10ml. ×1000
The amount of ammonium thiocyanate invading the rock sample, mng/kg: Where m
SY/ T 5343-94
Vi is the volume of the filtrate used to soak the rock sample, mL;
G is the weight of the rock sample, g.
b. The amount of drilling fluid filtrate invading the rock sample is calculated according to formula (3), m
Where: V,
The amount of drilling fluid filtrate invading the rock sample, mL/kgm—the concentration of ammonium thiocyanate in the drilling fluid, mg/mL. 4.2 Pyridine benzidine colorimetric method
4.2.1 Principle
Cyanide or thiocyanide is oxidized with bromine water to generate cyanogen bromide. Excess bromine is removed with a reducing agent. Pyridine and benzidine hydrochloride are added. This kind of aminocyclic hydrocarbon compound (aniline, benzidine, β-amine, etc.) reacts with pyridine and cyanogen bromide to generate α-amino-substituted dihydropyridine bromide salt (orange-red dye).
This method uses benzidine, and the generated compound is red. When the concentration is low, it is light red. This can be used for colorimetric determination. 4,2.2 Instruments and reagents
Analytical pure reagents that meet national standards or industry standards, deionized water or water of equivalent purity are used during analysis. Drop bottle: 50mL:
Other equipment is the same as 4.1.2 a~1 and p
Pyridine;
d. Benzidine hydrochloride;
Sodium formate;
Saturated bromine water;
g hydrochloric acid.
4.2.3 Preparation
4.2.3.1 Prepare ammonium thiocyanate standard solution
For preparation method, refer to 4.1.3.1. Dilute the ammonium thiocyanate standard solution with a concentration of 20ug/1mL to a concentration of 1.0ug/mL. 4.2.3.2 Prepare 0.2g/L aluminum trichloride soaking solution (2g/L potassium chromium sulfate or aluminum nitrate solution can also be used). Follow the preparation method of 4.1.3.2.
4.2.3.3 Prepare sodium formate solution
Weigh 20.0g of sodium formate, add 100mL of deionized water to dissolve it, and store it in a bottle for later use. 4.2.3.4 Prepare benzidine hydrochloride solution
Weigh 5.0g benzidine hydrochloride into a beaker, add 100mL of 1+50 (volume ratio) hydrochloric acid solution to dissolve it, and store it in a bottle for later use.
4.2.3.5 Prepare pyridine solution
Mix 60mL pyridine with 40mL deionized water and 10mL concentrated hydrochloric acid, and store it in a bottle for later use. 4.2.3.6 Prepare color developing solution
Mix pyridine solution and benzidine hydrochloride solution in a ratio of 5+1 (volume ratio) (mix now when using). 4.2.4 Analysis of drilling fluid filtrate
4.2.4.1 Analysis steps:
a Follow the steps in 4.1.5.1(a):
b Pipette 1.00mL of drilling fluid filtrate into a 100mL volumetric flask, dilute to the mark with deionized water and shake well; Pipette 1.00mL of the solution in 4.2.4.1(b) into a 10 or 25mL colorimetric tube, dilute to 5mL with deionized water (sample c
tube);
SY/ T 534394
d. Take a set of 10mL (or 25mL) colorimetric tubes: add 0.000.50, 1.00, 1.50.2.00.3.00:4.00mL of 1.0ug/mL ammonium thiocyanate standard solution respectively, and dilute to 5mL (standard tube) with deionized water: e. Add about 0.2mL of saturated bromine water to the sample tube and the standard tube respectively to make the solution yellow: f. Add sodium formate dropwise to the tubes in 4.2.4.1(e) until the solution is colorless; g. Add 3.50mL of colorimetric solution (4.2.3.6) to the tubes in 4.2.4.1() respectively, dilute to 10mL with deionized water, shake the hook and let it stand for 10min, then compare with the standard tube, and perform visual colorimetric (or instrument, select a wavelength of 560nm) determination (the colorimetric time should not exceed 30min).
4.2.4.2 Calculation:
The concentration of ammonium thiocyanate in the drilling fluid filtrate is calculated according to formula (4), 10
Wherein: m——the content of ammonium thiocyanate found from the standard curve (or measured by visual colorimetry), ug. 4.2.5 Analysis of rock samples
4.2.5.1 Analysis steps:
a. The operation is carried out according to 4.1.6.1(a) to 4.1.6.1(c);4
b. 5mL of the filtered filtrate of 4.1.6.1(c) is respectively taken and placed in a 10mL colorimetric tube, and 5mL of the filtered solution of 4.1.3.2 is taken and placed in another 10mL colorimetric tube as a blank sample; c. The following operations are carried out according to 4.2.4.1(e) to 4.2.4.1(g). 4.2.5.2 Calculation shall be in accordance with 4.1.6.2.
4.3 Precautions
4.3.1 When the voltage of the power supply is relatively stable and the instrument is used for colorimetry, the iron salt colorimetry or pyridine benzidine colorimetry shall be used. 4.3.2 When the voltage of the power supply is unstable or there is no colorimeter, the pyridine benzidine visual colorimetry shall be used. 5 Classification of the amount of drilling fluid filtrate invading the core (see Table 1) Table 1
Classification of the amount of drilling fluid filtrate invading the core
Classification of filtrate invading amount
Filtrate invading amount V, mL / kg
Micro invading
2.000g benzidine hydrochloride is placed in a beaker, and 100mL of 1+50 (volume ratio) hydrochloric acid solution is added to dissolve it, and stored in a bottle for later use.
4.2.3.5 Preparation of pyridine solution
Mix 60mL pyridine with 40mL deionized water and 10mL concentrated hydrochloric acid, and store in a bottle for later use. 4.2.3.6 Preparation of color developing solution
Mix pyridine solution and benzidine hydrochloride solution in a ratio of 5+1 (volume ratio) (mix now when using). 4.2.4 Analysis of drilling fluid filtrate
4.2.4.1 Analysis steps:
a Follow the steps in 4.1.5.1(a):
b Pipette 1.00mL of drilling fluid filtrate into a 100mL volumetric flask, dilute to the mark with deionized water and shake well; Pipette 1.00mL of the solution in 4.2.4.1(b) into a 10 or 25mL colorimetric tube, dilute to 5mL with deionized water (sample c
tube);
SY/ T 534394
d. Take a set of 10mL (or 25mL) colorimetric tubes: add 0.000.50, 1.00, 1.50.2.00.3.00:4.00mL of 1.0ug/mL ammonium thiocyanate standard solution respectively, and dilute to 5mL (standard tube) with deionized water: e. Add about 0.2mL of saturated bromine water to the sample tube and the standard tube respectively to make the solution yellow: f. Add sodium formate dropwise to the tubes in 4.2.4.1(e) until the solution is colorless; g. Add 3.50mL of colorimetric solution (4.2.3.6) to the tubes in 4.2.4.1() respectively, dilute to 10mL with deionized water, shake the hook and let it stand for 10min, then compare with the standard tube, and perform visual colorimetric (or instrument, select a wavelength of 560nm) determination (the colorimetric time should not exceed 30min).
4.2.4.2 Calculation:
The concentration of ammonium thiocyanate in the drilling fluid filtrate is calculated according to formula (4), 10
Wherein: m——the content of ammonium thiocyanate found from the standard curve (or measured by visual colorimetry), ug. 4.2.5 Analysis of rock samples
4.2.5.1 Analysis steps:
a. The operation is carried out according to 4.1.6.1(a) to 4.1.6.1(c);4
b. 5mL of the filtered filtrate of 4.1.6.1(c) is respectively taken and placed in a 10mL colorimetric tube, and 5mL of the filtered solution of 4.1.3.2 is taken and placed in another 10mL colorimetric tube as a blank sample; c. The following operations are carried out according to 4.2.4.1(e) to 4.2.4.1(g). 4.2.5.2 Calculation shall be in accordance with 4.1.6.2.
4.3 Precautions
4.3.1 When the voltage of the power supply is relatively stable and the instrument is used for colorimetry, the iron salt colorimetry or pyridine benzidine colorimetry shall be used. 4.3.2 When the voltage of the power supply is unstable or there is no colorimeter, the pyridine benzidine visual colorimetry shall be used. 5 Classification of the amount of drilling fluid filtrate invading the core (see Table 1) Table 1
Classification of the amount of drilling fluid filtrate invading the core
Classification of filtrate invading amount
Filtrate invading amount V, mL / kg
Micro invading
2.000g benzidine hydrochloride is placed in a beaker, and 100mL of 1+50 (volume ratio) hydrochloric acid solution is added to dissolve it, and stored in a bottle for later use.
4.2.3.5 Preparation of pyridine solution
Mix 60mL pyridine with 40mL deionized water and 10mL concentrated hydrochloric acid, and store in a bottle for later use. 4.2.3.6 Preparation of color developing solution
Mix pyridine solution and benzidine hydrochloride solution in a ratio of 5+1 (volume ratio) (mix now when using). 4.2.4 Analysis of drilling fluid filtrate
4.2.4.1 Analysis steps:
a Follow the steps in 4.1.5.1(a):
b Pipette 1.00mL of drilling fluid filtrate into a 100mL volumetric flask, dilute to the mark with deionized water and shake well; Pipette 1.00mL of the solution in 4.2.4.1(b) into a 10 or 25mL colorimetric tube, dilute to 5mL with deionized water (sample c
tube);
SY/ T 534394
d. Take a set of 10mL (or 25mL) colorimetric tubes: add 0.000.50, 1.00, 1.50.2.00.3.00:4.00mL of 1.0ug/mL ammonium thiocyanate standard solution respectively, and dilute to 5mL (standard tube) with deionized water: e. Add about 0.2mL of saturated bromine water to the sample tube and the standard tube respectively to make the solution yellow: f. Add sodium formate dropwise to the tubes in 4.2.4.1(e) until the solution is colorless; g. Add 3.50mL of colorimetric solution (4.2.3.6) to the tubes in 4.2.4.1() respectively, dilute to 10mL with deionized water, shake the hook and let it stand for 10min, then compare with the standard tube, and perform visual colorimetric (or instrument, select a wavelength of 560nm) determination (the colorimetric time should not exceed 30min).
4.2.4.2 Calculation:
The concentration of ammonium thiocyanate in the drilling fluid filtrate is calculated according to formula (4), 10
Wherein: m——the content of ammonium thiocyanate found from the standard curve (or measured by visual colorimetry), ug. 4.2.5 Analysis of rock samples
4.2.5.1 Analysis steps:
a. The operation is carried out according to 4.1.6.1(a) to 4.1.6.1(c);4
b. 5mL of the filtered filtrate of 4.1.6.1(c) is respectively taken and placed in a 10mL colorimetric tube, and 5mL of the filtered solution of 4.1.3.2 is taken and placed in another 10mL colorimetric tube as a blank sample; c. The following operations are carried out according to 4.2.4.1(e) to 4.2.4.1(g). 4.2.5.2 Calculation shall be in accordance with 4.1.6.2.
4.3 Precautions
4.3.1 When the voltage of the power supply is relatively stable and the instrument is used for colorimetry, the iron salt colorimetry or pyridine benzidine colorimetry shall be used. 4.3.2 When the voltage of the power supply is unstable or there is no colorimeter, the pyridine benzidine visual colorimetry shall be used. 5 Classification of the amount of drilling fluid filtrate invading the core (see Table 1) Table 1
Classification of the amount of drilling fluid filtrate invading the core
Classification of filtrate invading amount
Filtrate invading amount V, mL / kg
Micro invading
2.00
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.