CN102704912B - Determining method for crushing work ratio coefficient of roller bit - Google Patents

Abstract

The present invention relates to a method for measuring the breaking specific work coefficient of a roller cone bit. The measuring method for the breaking specific work coefficient of a roller cone bit: 1. Sampling the rock cuttings that are drilled into the stratum by the drill bit Z to be evaluated; 2. Determination of the maximum particle size and minimum particle size value of the sampling cuttings; three, determining the fractal dimension of the sampling cuttings, four, drawing and measuring the equivalent area diagram of the drill bit breaking specific power coefficient, and measuring the area of the graphic T by a computer program. p , p is the specific work coefficient of drill bit breaking. The required parameters of the present invention can be obtained only by simple measurement of cuttings, and are easy to be applied on site; the present invention can quickly judge the quality of the energy consumption index of the drill bit by comparing the area size of the equivalent area pattern of the broken specific work coefficient.

Description

A method for measuring the specific work coefficient of the crushing of the roller cone bit

1. Technical field:

The invention relates to a method for measuring the breaking specific work coefficient of a drill bit, which is mainly applied in the fields of petroleum engineering, mining engineering, etc., and specifically relates to a method for measuring the breaking specific work coefficient of a roller cone bit.

2. Background technology:

In 1867, Rittinger proposed the classic theory of fracture energy-size relationship. The energy required for the rock breaking process is proportional to the new surface area of the rock during the breaking process. Xie Heping explained in his book "Introduction to Fractal Rock Mechanics" that the rock breaking process has fractal The fracture energy calculation method of fractal crushing is given based on the Rittinger theory: when the rock with a scale of R is broken into debris particles with a scale of r , the energy required to break a unit volume of rock is , is the material constant, is the fractal dimension of cuttings, a large number of measurement results prove that . consider , so the above formula simplifies to . The cuttings actually produced during the drilling process are a mixture of multiple groups of particles with different particle sizes. Therefore, when the rock with a unit volume scale of R is broken into k groups with a particle size of r _i ( ) The total energy required for the cuttings mixture composed of particles is , Breaking specific work, its concept is the energy required to break a unit volume of rock; is the mass of cuttings with particle size r _i , is the total mass of cuttings, and . here will It is called the breaking specific work coefficient, and the breaking specific work coefficient can be used to evaluate the energy consumption index of the drill bit for rock breaking.

3. Contents of the invention:

The purpose of the present invention is to provide a method for measuring the specific work coefficient of the crushing of the roller cone bit. The method realizes the evaluation of the energy consumption index of the bit by measuring the relevant parameters of the cuttings sample.

The technical solution adopted by the present invention to solve the technical problems is: the measuring method of the broken specific work coefficient of this roller cone bit:

1. Sampling the upturned rock cuttings drilled into the stratum by bit Z to be evaluated,

Use the LWD geosteering monitor while drilling to monitor the layers drilled by the drill bit, and perform rock-breaking drilling on the target layer A. During the process of drilling into the target layer A, samples are taken three times, and the sampling positions are respectively 0.5 from the top of the target layer A. meters, 0.5 meters in the middle and 0.5 meters in the bottom; when drilling to the sampling position where cuttings are to be collected, turn off the rotary power system of the drilling tool, the drilling fluid circulation system continues to work normally, and clean the borehole until no cuttings are returned. , close the drilling fluid circulation system, pull out the drill pipe, install the drill bit Z to be evaluated, and lower the drill pipe; install cuttings collection screens at the outlet pipe of the drilling fluid on the ground. The screens are stacked in four layers from top to bottom, and screened from top to bottom The eye diameters are 15mm, 8mm, 3mm, and 0.3mm respectively; use a metal mesh sieve with a mesh diameter of 20mm to screen out rocks larger than 20mm in the sampling cuttings;

2. Determination of the maximum particle size and minimum particle size of the sampled cuttings; use a test sieve with a mesh diameter of 0.3mm ~1.5mm. There are 13 test sieves in total. The eye diameter is 0.1mm larger, , to sieve cuttings with a particle size of 0.3mm~3mm, first use a test sieve with a mesh diameter of 0.3mm, when the i -th test sieve is used to sieve cuttings, a small amount of cuttings leaks out, and If the mass ratio of the leaked cuttings is 0.2%~0.5%, the sieve diameter r _i of the test sieve of the i group is the minimum particle size r _min of the cuttings sample; a total of 11 groups of test sieves with a sieve diameter of 10mm~20mm are used , to sieve the cuttings, the test sieve of group j+1 is 1mm smaller than the test sieve of group j , ; Firstly, use a test sieve with a mesh diameter of 20mm, and use the test sieve j of the test sieve to sieve the cuttings . The sieve diameter n _j of the group test sieve is the maximum particle size of the cuttings sample; if the mass ratio of remaining cuttings on the sieve is greater than 0.5%, and there is no remaining cuttings on the sieve when the j -1 group of test sieves is used to sieve the cuttings For cuttings, use a test sieve with a mesh diameter between n _j + 0.1mm and n j _-1 -0.1mm. There are 9 groups of test sieves in total. The eye diameter is 0.1mm larger, , to sieve the cuttings, when the cuttings are screened by the k -th group of test sieves, there are remaining cuttings on the sieve, and when the mass ratio of the remaining cuttings on the sieve is 0.2%~0.5%, the k -th group of test sieves The sieve diameter l _k is the maximum particle size r _max of the cuttings sample, and then the determination of the maximum particle size and minimum particle size of the sampled cuttings is completed.

3. To measure the fractal dimension of the sampled cuttings, first weigh the total mass M of the sampled cuttings, and use a test sieve with a mesh diameter of 15 mm to sieve the cuttings whose particle size is less than r ₁ =15 mm, and call its mass M ₁ ; Then use a test sieve with a sieve diameter of 10mm to sieve the cuttings with a particle size of less than 15mm, and weigh the cuttings with a particle size of less than r ₂ =10mm under the sieve as M ₂ ; repeat the above steps in turn, and weigh The mass M ₃ of cuttings with a particle size smaller than r ₃ =7 mm is obtained, the mass M ₄ of cuttings with a particle size smaller than r ₄ =5 mm is obtained, and the mass M ₅ of cuttings with a particle size smaller than r ₅ =2 mm is weighed. Draw five scatter points separately on the graph paper And carry out linear regression, measure the slope b of the regression line, and measure the fractal dimension of cuttings D =3- b ;

4. Draw and measure the equivalent area diagram of the specific work coefficient of the drill bit, compile the drawing program in the computer, and draw the curve on the Cartesian coordinate system , x=0, And the closed figure T composed of four lines of y = 1, the area of the figure T is measured by computer program as p , p is the specific work coefficient of drill bit crushing, In the formula ;

In the above plan, the process of sampling the target layer A three times is as follows: put the drilling fluid surface return nozzle into the cuttings collection screen, open the drilling fluid circulation system and the drilling tool rotation power system, and drill the first sampling position Finally, turn off the drilling tool rotation power system, the drilling fluid circulation system will carry the cuttings to the ground, and start to collect the cuttings. At the original drilling fluid filtering device, turn on the drilling tool rotation power system again for normal drilling. When drilling to the second sampling position, turn off the drilling tool rotation power system and clean the wellbore until no cuttings are left on it. Return, close the drilling fluid circulation system, put the drilling fluid ground return nozzle into the cuttings collection screen, open the drilling tool rotation power system and drilling fluid circulation system to complete the drilling of the second sampling position, and close the drilling tool rotation power system , and start the second cuttings sampling, and the second sampling is completed until there are no more cuttings returned; put the drilling fluid ground return nozzle back to the original drilling fluid filtering device, and then open the drilling tool again The rotary power system performs normal drilling. When drilling to the third sampling position, the rotary power system of the drilling tool is turned off, the wellbore is cleaned until no cuttings are returned, the drilling fluid circulation system is closed, and the drilling fluid is returned to the surface. Put the cuttings collection sieve into the nozzle, open the drilling tool rotation power system and the drilling fluid circulation system to complete the drilling of the third sampling position, close the drilling tool rotation power system, and start the third cuttings sampling, until no longer The third sampling was completed until there were rock debris returned.

In the method for measuring the crushing specific work coefficient of the roller cone bit in the above scheme, when comparing the rock-breaking energy consumption of multiple groups of drill bits, the equivalent area diagrams of the crushing specific work coefficients of each group of drill bits are drawn in the same coordinate system in turn according to the above steps, through Comparing the size of the graphic area can directly determine the energy consumption of the drill bit for rock breaking.

Beneficial effect:

1. The cuttings sampling method provided by the present invention is to first stop drilling when the drill bit reaches the target layer, use the drilling fluid to remove the rock and broken cuttings in the non-sampling layer in the wellbore, and then break the sampling layer while the drilling fluid circulation system When cuttings are returned, stop drilling after the sampling layer is broken until no more cuttings are returned, and the collection of cuttings samples is completed. This collection method can ensure that the collected cuttings are all from the target horizon, and at the same time ensure the completeness of the cuttings samples.

2. Sampling cuttings three times at the top 0.5m, 0.5m in the middle and 0.5m in the lower part of the target layer can effectively improve the standardization of sampling cuttings and ensure the measurement accuracy of cuttings-related parameters.

3. The method for measuring the drill bit breaking specific work coefficient provided by the present invention can quickly judge the quality of the drill bit energy consumption index by comparing the area size of the equivalent area pattern of the breaking specific work coefficient when multiple groups of drill bits are optimized, and at the same time The parameters required by the method can be obtained only by simple measurement of cuttings, which is easy to be applied on site.

4. Description of drawings:

Figure 1 is a schematic diagram of the equivalent area graph T ₁ of the crushing specific work coefficient of the drill bit HJT617;

Fig. 2 is a schematic diagram of the equivalent area graph T ₂ of the crushing specific work coefficient of the drill bit HJT737;

FIG. 3 is a schematic diagram of the area comparison between T ₁ and T ₂ .

5. Specific implementation methods:

Below in conjunction with accompanying drawing, the present invention will be further described:

Example 1:

The rock-breaking energy consumption index of two sets of roller cone bits HJT617 and HJT737 commonly used in the volcanic formation of block X of an oilfield is evaluated. The 3500m~3600m volcanic strata of Well XS1 was drilled with the HJT617 drill bit, and three target strata of 3500m~3500.5m, 3550m~3550.5m, and 3599.5~3600m were used to sample cuttings three times using the steps provided by the present invention, and finally 120kg of cuttings were collected. . Use the second step provided by the present invention to measure the maximum particle size r _max =18mm and the minimum particle size r _min =0.5mm of the sampled cuttings; use the third step provided by the present invention to measure the fractal dimension D ₁ =2.26 of the cuttings; apply this Step 4 provided by the invention draws the equivalent area graph T ₁ of the crushing specific work coefficient of the drill bit HJT617 (see Fig. 1 ), and the area of the graph T ₁ is determined to be 0.312.

Using the steps provided by the present invention, the process of sampling the target layer A for three times is as follows: put the drilling fluid ground return nozzle into the cuttings collection screen, open the drilling fluid circulation system and the drilling tool rotation power system, and drill 3500m At ~3500.5m, turn off the drilling tool rotation power system, the drilling fluid circulation system will carry the cuttings to the ground, and start to collect the cuttings. Put the hole back to the original drilling fluid filtering device, and then turn on the rotary power system of the drilling tool again for normal drilling. When drilling to 3550m, turn off the rotary power system of the drilling tool, and clean the wellbore until no cuttings are returned. Close the drilling fluid circulation system, put the drilling fluid ground return nozzle into the cuttings collection screen, open the drilling tool rotation power system and drilling fluid circulation system to complete the drilling of the 3550m~3550.5m layer, close the drilling tool rotation power system, And start the second cuttings sampling, and the second sampling is completed until no more cuttings are returned; put the drilling fluid ground return nozzle back to the original drilling fluid filtering device, and then turn on the drilling tool again to rotate The power system performs normal drilling. When drilling to 3599.5m, turn off the drilling tool rotation power system, clean the wellbore until no cuttings are returned, close the drilling fluid circulation system, and put the drilling fluid back into the rock at the ground return nozzle. Cuttings collection screen, turn on the drilling tool rotation power system and drilling fluid circulation system to complete the drilling of the 3599.5~3600m layer, turn off the drilling tool rotation power system, and start the third cuttings sampling, until there is no more rock return So far the third sampling is completed.

Use step 2 provided by the present invention to measure the process of the maximum particle size and the minimum particle size value of the sampled cuttings: use two groups of test sieves with a mesh diameter of 19mm and 20mm to screen the cuttings without remaining cuttings on the sieve, When the cuttings are screened with a test sieve with a mesh diameter of 18mm, there are residual cuttings on the sieve, and the weight of the remaining cuttings on the sieve is 0.3kg, accounting for 0.25% of the total mass of cuttings. The maximum particle size of cuttings is r _max =18mm. When using a test sieve with a sieve diameter of 0.3mm~0.4mm to sieve cuttings with a particle size range of 0.3mm~3mm, there is no cuttings leakage under the sieve. Leakage, weighing the quality of the cuttings of the leakage is 0.4kg, accounting for 0.3% of the total mass of cuttings, the minimum particle size of cuttings r _min =0.5mm.

Use step three provided by the present invention to measure the fractal dimension of sampling cuttings: use a test sieve with a mesh diameter of 15 mm to sieve cuttings with a particle size less than r ₁ =15 mm, and call its quality M ₁ =103 kg; Then use a test sieve with a sieve diameter of 10mm to sieve the cuttings with a particle size of less than 15mm, and weigh the cuttings with a particle size of less than r ₂ =10mm under the sieve, and weigh its mass as M ₂ =76.8kg; repeat the above steps in turn , the mass of rock cuttings with a particle size smaller than r ₃ =7mm was weighed M ₃ =59.2kg, the mass of rock chips with a particle size smaller than r ₄ = _5mm was weighed M ₄ = 48.3kg , and the mass of rock chips with a particle size of Chip mass M ₅ =23kg, draw five scatter points on the double-logarithmic coordinate paper And carry out linear regression, determine the slope of the regression line b = 0.74, and measure the fractal dimension of cuttings D = 3- b = 2.26;

Use step 4 provided by the present invention to draw the broken specific work coefficient equivalent area graph T ₁ of drill bit HJT617: draw the curve in the Cartesian coordinate system of the computer program interface prepared , x =0, And y = 1 four lines, get a closed figure T ₁ composed of four lines, the area of figure T ₁ is measured as 0.312 by the programmed program.

The 3600m~3715m volcanic strata of Well XS1 is drilled with the HJT737 drill bit, and the cuttings are sampled for three target formations of 3600m~3600.5m, 3655m~3655.5m and 3714.5~3715m using the rock step provided by the present invention, and finally the cuttings are collected 127.5kg; use the second step provided by the present invention to measure the maximum particle size r _max =18mm and the minimum particle size r _min =0.4mm of the sampled cuttings; use the third step provided by the present invention to measure the fractal dimension of the cuttings D ₂ =2.35 ; Apply step 4 provided by the present invention to draw the equivalent area graph T ₂ of the broken specific work coefficient of the drill bit HJT737 (see Figure 2). _The area of figure T2 was determined to be 0.378.

Using the steps provided by the present invention, the process of sampling the target layer A for three times is as follows: put the drilling fluid ground return nozzle into the cuttings collection screen, open the drilling fluid circulation system and the drilling tool rotation power system, and drill 3600m At ~3600.5m, turn off the drilling tool rotation power system, and the drilling fluid circulation system will carry the cuttings to the ground and start collecting cuttings. Put the hole back to the original drilling fluid filtering device, and then turn on the rotary power system of the drilling tool again for normal drilling. When drilling to 3655m, turn off the rotary power system of the drilling tool, and clean the wellbore until no cuttings are returned. Close the drilling fluid circulation system, put the drilling fluid ground return nozzle into the debris collection screen, open the drilling tool rotation power system and drilling fluid circulation system to complete the drilling of the 3655m~3655.5m layer, close the drilling tool rotation power system, And start the second cuttings sampling, and the second sampling is completed until no more cuttings are returned; put the drilling fluid ground return nozzle back to the original drilling fluid filtering device, and then turn on the drilling tool again to rotate The power system performs normal drilling. When drilling to 3714.5m, turn off the drilling tool rotation power system, clean the wellbore until no cuttings are returned, close the drilling fluid circulation system, and put the drilling fluid ground return nozzle into the rock. Cuttings collection screen, turn on the drilling tool rotation power system and drilling fluid circulation system to complete the drilling of the 3714.5~3715m layer, turn off the drilling tool rotation power system, and start the third cuttings sampling, until there is no more rock return So far the third sampling is completed.

Use step 2 provided by the present invention to measure the process of the maximum particle size and the minimum particle size value of the sampled cuttings: use two groups of test sieves with a mesh diameter of 19mm and 20mm to screen the cuttings without remaining cuttings on the sieve, When the cuttings were screened with a test sieve with a mesh diameter of 18mm, there were residual cuttings on the sieve, and the weight of the remaining cuttings on the sieve was 0.35kg, accounting for 0.27% of the total mass of cuttings. The maximum particle size of cuttings was r _max =18mm. When using a test sieve with a mesh diameter of 0.3mm to sieve cuttings with a particle size range of 0.3mm to 3mm, there is no leakage of cuttings under the sieve. When the diameter of the mesh is 0.4mm, there is leakage of cuttings. Weigh The mass of cuttings in the leakage is 0.6kg, accounting for 0.47% of the total mass of cuttings, and the minimum particle size of cuttings is r _min =0.4mm.

Use step 3 provided by the present invention to measure the process of the fractal dimension of sampling cuttings: use the test sieve with a mesh diameter of 15mm to sieve the cuttings with a particle size less than r ₁ =15mm, claim its quality as M ₁ =116.3kg ; Then use a test sieve with a sieve diameter of 10mm to sieve the cuttings with a particle size of less than 15mm, and weigh the cuttings with a particle size of less than r ₂ =10mm under the sieve, and weigh its mass as M2=88.7kg; repeat the above steps in turn , Weigh the mass of cuttings with a particle size smaller than r ₃ =7mm M3=69.4kg, weigh the mass of cuttings with a particle size smaller than r ₄ =5mm M4=54.2kg, weigh the mass of cuttings with a particle size smaller than r ₅ =2mm M5=31.7kg, draw five scatter points respectively on the double-logarithmic coordinate paper And carry out linear regression, determine the slope of the regression line b = 0.65, and measure the fractal dimension of cuttings D = 3- b = 2.35;

Use step 4 provided by the present invention to draw the broken specific work coefficient equivalent area figure T ₂ of the drill bit HJT617: draw the curve in the Cartesian coordinate system of the computer program interface prepared , x =0, And y = 1 four lines, get a closed figure T ₂ composed of four lines, the area of figure T ₂ is measured as 0.378 by the prepared program.

When it is only necessary to measure the energy consumption indicators of the _two groups of drill bits, draw the graph T1 and graph T2 in the same coordinate (see Figure ₃ ), the area _of graph T1 < the area of graph T2, and the crushing specific work of the drill bit _HJT617 <The crushing specific work of the drill bit HJT737.

Claims (2)

1. a kind of assay method of rock bit specific energy coefficient, it is characterised in that：This rock bit specific energy coefficient Assay method：

First, sample to returning landwaste on drill bit Z to be evaluated drillings stratum, monitored using LWD geosteering monitoring while drillings instrument The layer position of drill bit drilling, broken rock drilling is carried out to destination layer position A, and during drilling destination layer position A three sub-samplings are carried out respectively, is taken Sample position is respectively at 0.5 meter of 0.5 meter of destination layer position A tops, 0.5 meter of middle part and bottom；When the sampling for being drilled into landwaste to be collected During position, the rotary power system of drilling tool is closed, drilling-fluid circulation system continues normal work, and cleaning well is to there is no longer landwaste On return, close drilling-fluid circulation system, rise drilling rod install drill bit Z to be evaluated, under enter drilling rod；In ground drilling liquid outlet Place install landwaste collection screen, sieve from top to bottom four stacking put, from top to bottom mesh diameter be respectively 15mm, 8mm, 3mm, 0.3mm；The sillar in sampling landwaste more than 20mm is screened out using the wire-mesh screen of a diameter of 20mm of mesh；

2nd, maximum particle diameter, the minimum grain size value of sampling landwaste are determined；Using the testing sieve of mesh diameter 0.3mm ~ 1.5mm, test 13 groups altogether of sieve, thei+ 1 group testing sieve comparesiThe big 0.1mm of mesh diameter of group testing sieve,, to particle diameter 0.3mm ~ The landwaste of 3mm is sieved, first by the testing sieve of mesh diameter 0.3mm, when using toiGroup testing sieve is carried out to landwaste There is a small amount of landwaste to leak down during screening, and the landwaste mass ratio for leaking down is 0.2% ~ 0.5%, theniThe mesh diameter of group testing siever _i For the minimum grain size of landwaste sampler _min；Amount to 11 groups using the testing sieve of mesh diameter 10mm ~ 20mm, landwaste sieved, The group of jth+1 testing sieve comparesjThe little 1mm of mesh diameter of group testing sieve,；First by the test of mesh diameter 20mm Sieve, uses thejGroup testing sieve has remaining landwaste when sieving to landwaste on sieve, and sieve upper residue landwaste mass ratio 0.2% ~ When 0.5%, thenjThe mesh diameter of group testing sieven _jFor the maximum particle diameter of landwaste sample；If remaining landwaste mass ratio is more than on sieve 0.5%, and usejWithout remaining landwaste on sieve when -1 group testing sieve is sieved to landwaste, at this moment using mesh diameter in n_j+ 0.1mm and n_j-1Testing sieve between -0.1mm, testing sieve amounts to 9 groups, andk+ 1 group testing sieve compareskThe mesh of group testing sieve is straight The big 0.1mm in footpath,, landwaste is sieved, usekThere is remaining rock on sieve when group testing sieve is sieved to landwaste Bits, and sieve upper residue landwaste mass ratio at 0.2% ~ 0.5%, then thekThe mesh diameter of group testing sievel _kFor landwaste sample most Big particle diameterr _max, and then complete the measure of sampling landwaste maximum particle diameter and minimum grain size value；

3rd, the fractal dimension of sampling landwaste is determined, gross mass M of sampling landwaste is weighed first, with the examination of a diameter of 15mm of mesh Test sieve undersize footpath to be less thanr ₁The landwaste of=15mm, its quality is called M₁；Then with the testing sieve that sieve diameter is 10mm to particle diameter Landwaste less than 15mm is sieved, and undersize footpath is less thanr ₂The landwaste of=10mm, its quality is called M₂；It is repeated in above-mentioned step Suddenly, claim particle diameter is less thanr ₃The landwaste mass M of=7mm₃, claim particle diameter is less thanr ₄The landwaste mass M of=5mm₄, claim particle diameter is less thanr ₅ The landwaste mass M of=2mm₅, draw five scatterplots respectively on log-log paper, and linear regression is carried out, the X of five scatterplots It is worth and is, Y value is, determine the slope of regression straight lineb, measure landwaste fractal dimensionD=3-b；

4th, the equivalent area-graph of drill bit specific energy coefficient is drawn and is determined, mapping program is woven in computer, sat at right angle Mark fastens drafting curve、x=0、AndyThe closed figure T that=1 four line is constituted, by computer The area of program determination figure T isp,pAs drill bit specific energy coefficient,In formula。

2. the assay method of rock bit specific energy coefficient according to claim 1, it is characterised in that：Described gear wheel The assay method of drill bit specific energy coefficient can take in the broken rock of more multigroup drill bit, successively according to four steps same Draw the equivalent area-graph of each group drill bit specific energy coefficient in one coordinate system respectively, can by comparing the stool and urine of graphics field Directly judge drill bit broken rock energy consumption height.