CN108509675B - Method for calculating hole diameter and clearance by density logging while drilling - Google Patents
Method for calculating hole diameter and clearance by density logging while drilling Download PDFInfo
- Publication number
- CN108509675B CN108509675B CN201810125774.5A CN201810125774A CN108509675B CN 108509675 B CN108509675 B CN 108509675B CN 201810125774 A CN201810125774 A CN 201810125774A CN 108509675 B CN108509675 B CN 108509675B
- Authority
- CN
- China
- Prior art keywords
- density
- following
- clearance
- drilling
- calculating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 23
- 238000005553 drilling Methods 0.000 title claims abstract description 21
- 238000005259 measurement Methods 0.000 claims description 15
- 239000002002 slurry Substances 0.000 claims description 5
- 238000002474 experimental method Methods 0.000 claims description 4
- 238000000342 Monte Carlo simulation Methods 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 claims description 3
- 238000012417 linear regression Methods 0.000 claims description 3
- 238000012423 maintenance Methods 0.000 abstract description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000007792 addition Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
- E21B49/005—Testing the nature of borehole walls or the formation by using drilling mud or cutting data
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Fluid Mechanics (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Theoretical Computer Science (AREA)
- Remote Sensing (AREA)
- Geophysics (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
The invention discloses a method for calculating a hole diameter and a clearance by density logging while drilling, which belongs to the technical field of oil field logging and specifically comprises the following steps: first, X is obtainedLAnd XLA functional relation; secondly, the gap size t is obtainedm(ii) a Finally, the radius D of the borehole is obtained. The invention can cover the measuring blind area of the hole diameter measured by ultrasonic waves in the range of calculating the clearance, and has wider application range to mud than the ultrasonic measuring clearance and hole diameter; in addition, from the engineering point of view, the invention solves the problems of inconvenient maintenance, high maintenance cost, very expensive instrument cost and the like of the ultrasonic instrument.
Description
Technical Field
The invention belongs to the technical field of oil field logging, and particularly relates to a method for calculating a hole diameter and a gap by density logging while drilling.
Background
In the logging while drilling, the change of the borehole diameter (borehole size) influences the measurement precision of the instrument, not only is an important parameter for eliminating the influence of porosity logging and lithologic density logging boreholes eliminated, but also the amount of cement required by well cementation can be estimated by utilizing the borehole diameter information, the position of a fracture zone in the oil exploitation process is positioned, and the stability of the borehole wall, such as shrinkage, collapse and drill jamming, borehole expansion and the like in the drilling process, is intuitively and vividly reflected. The traditional cable logging is to measure the borehole diameter after drilling, and the size of the borehole is measured by contacting the wall of the borehole by a pushing arm in the process of lifting the instrument. While logging while drilling is to measure underground information in the rotary advancing process of drilling, which is greatly different from the instrument structure and construction mode of cable logging and the measurement environment, so that a non-contact measurement mode is required for measuring the size of a borehole in logging while drilling.
At present, ultrasonic well diameter measurement is generally used in well logging while drilling, the distance between an instrument and a well wall is determined by utilizing ultrasonic echo time difference, and the well diameter size is calculated, but the ultrasonic signal is seriously attenuated due to the increase of mud specific gravity, the measurement reliability is reduced, so that the conventional measurement technology is only suitable for the mud specific gravity smaller than 1.3g/cm3And when the specific gravity of the slurry is more than 1.3g/cm3The reliability of the measurement under (1) is extremely poor. In addition, when the ultrasonic caliper works, aftershocks can be generated on the probe and the casing of the caliper, and a dead zone is generated during measurement of the caliper due to the fact that current of a circuit is very strong instantly when the ultrasonic waves are reflected, and the dead zone is basically within 3 cm. Thus, the accuracy of measuring parameters such as density, neutron porosity and the like is reduced. There is therefore a great limitation in measuring the hole diameter using ultrasonic waves.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention provides a method for calculating the hole diameter and the clearance by density logging while drilling, which has reasonable design, overcomes the defects of the prior art and has good effect.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for calculating the hole diameter and the clearance by density logging while drilling specifically comprises the following steps:
step 1: determining the weight X of the slurryLAnd XLThe functional relation specifically includes the following steps:
step 1.1: simulating the logging-while-drilling density by using Monte Carlo simulation to obtain the far density rhofarFormation density ρbMud density ρmAnd a gap dimension tmA value of (d);
step 1.2: using formula XL=(ρb-ρfar)/(ρb-ρm) Calculating XLA value of (d);
step 1.3: varying the gap dimension tmFormation density ρbAnd mud density ρmMultiple experiments are carried out to obtain the scatter combination (X)L1,(ρb-ρm)2,tm1)、(XL2,(ρb-ρm)2,tm2)……(XLi,(ρb-ρm)i,tmi) Wherein i is the number of measurements;
step 1.4: to obtain XL=f(ρb-ρm,tm) A functional relation;
step 2: determining the gap size tmThe method specifically comprises the following steps:
step 2.1: mixing XL=f(ρb-ρm,tm) The functional relation is deformed to obtain tm=g(XL,ρb-ρm);
Step 2.2: calculating the gap size t by using a multiple linear regression analysis methodmThe concrete formula is as follows:
tm=aXL+bXL 2+c(ρb-ρm)+d(ρb-ρm)2+eXL(ρb-ρm)
wherein a, b, c, d, e are coefficients, respectively;
and step 3: the method for obtaining the radius D of the borehole specifically comprises the following steps:
step 3.1: the sizes of three gaps are arbitrarily taken at positions of every 120 degrees;
step 3.2: the distance S between the axis of the instrument and the well wall is calculated by the following formula1、S2、S3;
S1=r+tm1;
S2=r+tm2;
S3=r+tm3;
Wherein, tm1、tm2、tm3Is the gap size, r is the radius of the instrument, S1、S2、S3The included angle between every two is 120 degrees,
for 3 three corners with d as a common edge, the following 3 trigonometric functions can be listed:
wherein d is the distance between the axis of the well and the axis of the instrument, and alpha is S1And d;
solving the equation system to obtain the radius D of the borehole, wherein the result is as follows:
where T is a temporary variable.
The following description is given of the basic principles of the invention:
the basic principle of the invention is a method for calculating the hole diameter and the clearance size based on the density logging while drilling. Mud weight XLIs determined by the formation density ρbAnd gap-filled mud density ρmDifference of (D) and gap thickness tmDetermined, mud weight XLDifference from formation density and mud density (p)b-ρm) And gap thickness tmFunctional relationship between:
XL∝(ρb-ρm)tm
where ρ isbIs the formation density value, ρmIs the mud density value, tmIs the size of the gap.
Wherein, for the weight X of the slurryLThe explanation of (a) is as follows:
in density logging while drilling, dual detectors are used to make measurements, the density measured by the detector that is farther from the source is called the far density, and the density measured by the detector that is closer to the source is called the near density. Because of the influence of the gap and the filling mud, the calculated far density and near density are not equal to the real density of the stratum, and the corresponding far density and near density are weighted values of the stratum density and the mud density at the moment.
ρfar=XLρm+(1-XL)ρb
Weight of mud deformed by XLComprises the following steps:
XL=(ρb-ρfar)/(ρb-ρm)
where ρ isfarIs a remote sonde measuring the density value of the formation.
The invention has the following beneficial technical effects:
according to the invention, on the basis of density logging while drilling, compared with a method of using ultrasonic distance measurement, the calculation of the clearance and the hole diameter can cover a blind area measured by using ultrasonic waves in the size range of the calculated clearance, and the application range of mud is improved; in addition, from the engineering point of view, the invention solves the problems of inconvenient maintenance, high maintenance cost, very expensive instrument cost and the like of the ultrasonic instrument.
Drawings
FIG. 1 is a schematic view of the geometry of the gap and the wellbore and instrumentation.
Wherein, 1-well wall; 2-the apparatus wall; 3-well axis; 4-instrument axis; 6-detecting the position of the stratum; 8-distance S from instrument axis to well wall1And the included angle of the distance from the axis of the well to the axis of the instrument; 9-distance S from the instrument axis to the borehole wall1(ii) a 10-distance S from the instrument axis to the borehole wall2(ii) a 11-distance S from the instrument axis to the borehole wall3。
Detailed Description
The invention is described in further detail below with reference to the following figures and detailed description:
the geometrical relationship between the gap and the borehole and the instrument is shown in figure 1.
A method for calculating the hole diameter and the clearance by density logging while drilling specifically comprises the following steps:
step 1: determining the weight X of the slurryLAnd XLThe functional relation specifically includes the following steps:
step 1.1: simulating the logging-while-drilling density by using Monte Carlo simulation to obtain the far density rhofarFormation density ρbMud density ρmAnd a gap dimension tmA value of (d);
step 1.2: using formula XL=(ρb-ρfar)/(ρb-ρm) Calculating XLA value of (d);
step 1.3: varying the gap dimension tmFormation density ρbAnd mud density ρmMultiple experiments are carried out to obtain the scatter combination (X)L1,(ρb-ρm)2,tm1)、(XL2,(ρb-ρm)2,tm2)……(XLi,(ρb-ρm)i,tmi) Wherein i is the number of measurements;
step 1.4: to obtain XL=f(ρb-ρm,tm) A functional relation;
step 2: determining the gap size tmThe method specifically comprises the following steps:
step 2.1: mixing XL=f(ρb-ρm,tm) The functional relation is deformed to obtain tm=g(XL,ρb-ρm);
Step 2.2: calculating the gap size t by using a multiple linear regression analysis methodmThe concrete formula is as follows:
tm=aXL+bXL 2+c(ρb-ρm)+d(ρb-ρm)2+eXL(ρb-ρm)
wherein a, b, c, d, e are coefficients, respectively;
and step 3: the method for obtaining the radius D of the borehole specifically comprises the following steps:
step 3.1: the sizes of three gaps are arbitrarily taken at positions of every 120 degrees;
step 3.2: the distance S between the axis of the instrument and the well wall is calculated by the following formula1、S2、S3;
S1=r+tm1;
S2=r+tm2;
S3=r+tm3;
Wherein, tm1、tm2、tm3Is the gap size, r is the radius of the instrument, S1、S2、S3The included angle between every two is 120 degrees,
for 3 three corners with d as a common edge, the following 3 trigonometric functions can be listed:
wherein d is the distance between the axis of the well and the axis of the instrument, and alpha is S1And d;
solving the equation system to obtain the radius D of the borehole, wherein the result is as follows:
where T is a temporary variable.
The platform of the experiment is Monte Carlo simulation software, data is simulated, the clearance and the well diameter processed by the calculation method of the invention are compared with the designed clearance and well diameter (such as tables 1 and 2), the feasibility of the invention is determined by analyzing errors, the table 1 is the comparison of the designed clearance and the calculated clearance, and the table 2 is the comparison of the designed well radius and the calculated radius.
TABLE 1 comparison of design gap to calculated gap
TABLE 2 comparison of design radius to calculated radius
Serial number | Design radius cm | Angle of rotation/degree | Gap size/cm | Calculating radius/cm | Error of the measurement |
1 | 12.9 | 0 | 0.093188 | 12.99319 | 0.09 |
2 | 12.9 | 22.5 | 0.310813 | 13.05561 | 0.16 |
3 | 12.9 | 45 | 0.542498 | 12.83261 | 0.07 |
4 | 12.9 | 67.5 | 1.358426 | 12.92321 | 0.02 |
5 | 12.9 | 90 | 1.9991 | 12.64862 | 0.25 |
6 | 12.9 | 112.5 | 3.032269 | 12.68757 | 0.21 |
7 | 12.9 | 135 | 3.976884 | 12.73243 | 0.17 |
8 | 12.9 | 157.5 | 4.691901 | 12.81796 | 0.08 |
9 | 12.9 | 180 | 5.011733 | 12.91173 | 0.01 |
From the above table 1, it can be seen that the difference between the calculated clearance value and the designed clearance value is 0.323794 (i.e. error) at most, the average error is 0.1641107cm, and the difference is almost the same as the accuracy of determining the clearance by using the ultrasonic echo time difference, but the range of the calculated clearance covers the measurement blind area of the ultrasonic caliper, and the limitation on the requirement of mud performance is relatively reduced; it can be seen from table 2 that the errors in the hole diameters calculated by the present invention are small, substantially approaching the designed wellbore size. As can be seen from tables 1 and 2, the method provided by the invention can effectively calculate the gap thickness and the hole diameter size, and therefore, the method provided by the invention can meet the requirement of obtaining the calculation result in engineering.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.
Claims (1)
1. A method for calculating the hole diameter and the clearance by density logging while drilling is characterized in that: the method specifically comprises the following steps:
step 1: determining the weight X of the slurryLAnd XLThe functional relation specifically includes the following steps:
step 1.1: simulating the logging-while-drilling density by using Monte Carlo simulation to obtain the far density rhofarFormation density ρbMud density ρmAnd a gap dimension tmA value of (d);
step 1.2: using formula XL=(ρb-ρfar)/(ρb-ρm) Calculating XLA value of (d);
step 1.3: varying the gap dimension tmFormation density ρbAnd mud density ρmMultiple experiments are carried out to obtain the scatter combination (X)L1,(ρb-ρm)2,tm1)、(XL2,(ρb-ρm)2,tm2)……(XLi,(ρb-ρm)i,tmi) Wherein i is the number of measurements;
step 1.4: to obtain XL=f(ρb-ρm,tm) A functional relation;
step 2: determining the gap size tmThe method specifically comprises the following steps:
step 2.1: mixing XL=f(ρb-ρm,tm) The functional relation is deformed to obtain tm=g(XL,ρb-ρm);
Step 2.2: calculating the gap size t by using a multiple linear regression analysis methodmThe concrete formula is as follows:
tm=aXL+bXL 2+c(ρb-ρm)+d(ρb-ρm)2+eXL(ρb-ρm)
wherein a, b, c, d, e are coefficients, respectively;
and step 3: the method for obtaining the radius D of the borehole specifically comprises the following steps:
step 3.1: the sizes of three gaps are arbitrarily taken at positions of every 120 degrees;
step 3.2: the distance S between the axis of the instrument and the well wall is calculated by the following formula1、S2、S3;
S1=r+tm1;
S2=r+tm2;
S3=r+tm3;
Wherein, tm1、tm2、tm3Is the gap size, r is the radius of the instrument, S1、S2、S3The included angle between every two is 120 degrees,
for 3 three corners with d as a common edge, the following 3 trigonometric functions can be listed:
wherein d is the distance between the axis of the well and the axis of the instrument, and alpha is S1And d;
solving the equation system to obtain the radius D of the borehole, wherein the result is as follows:
where T is a temporary variable.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201810125774.5A CN108509675B (en) | 2018-02-08 | 2018-02-08 | Method for calculating hole diameter and clearance by density logging while drilling |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201810125774.5A CN108509675B (en) | 2018-02-08 | 2018-02-08 | Method for calculating hole diameter and clearance by density logging while drilling |
Publications (2)
Publication Number | Publication Date |
---|---|
CN108509675A CN108509675A (en) | 2018-09-07 |
CN108509675B true CN108509675B (en) | 2021-10-26 |
Family
ID=63375594
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201810125774.5A Active CN108509675B (en) | 2018-02-08 | 2018-02-08 | Method for calculating hole diameter and clearance by density logging while drilling |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN108509675B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN117148331B (en) * | 2023-10-31 | 2023-12-26 | 中海油田服务股份有限公司 | Test system and test method of while-drilling ultrasonic imaging instrument |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5513528A (en) * | 1994-01-14 | 1996-05-07 | Schlumberger Technology Corporation | Logging while drilling method and apparatus for measuring standoff as a function of angular position within a borehole |
US6044326A (en) * | 1999-01-15 | 2000-03-28 | Dresser Industries, Inc. | Measuring borehole size |
CN103233727A (en) * | 2013-05-13 | 2013-08-07 | 中国石油大学(华东) | Inversion method of stratum shear wave velocity radial sections |
CN106646642A (en) * | 2016-12-29 | 2017-05-10 | 中国石油大学(华东) | Scanning type radioactive hole diameter measurement device and method |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7279677B2 (en) * | 2005-08-22 | 2007-10-09 | Schlumberger Technology Corporation | Measuring wellbore diameter with an LWD instrument using compton and photoelectric effects |
EP2241906B1 (en) * | 2009-04-17 | 2015-04-01 | Services Pétroliers Schlumberger | Method of determining density of underground formations using neutron-gamma ray measurements |
-
2018
- 2018-02-08 CN CN201810125774.5A patent/CN108509675B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5513528A (en) * | 1994-01-14 | 1996-05-07 | Schlumberger Technology Corporation | Logging while drilling method and apparatus for measuring standoff as a function of angular position within a borehole |
US6044326A (en) * | 1999-01-15 | 2000-03-28 | Dresser Industries, Inc. | Measuring borehole size |
CN103233727A (en) * | 2013-05-13 | 2013-08-07 | 中国石油大学(华东) | Inversion method of stratum shear wave velocity radial sections |
CN106646642A (en) * | 2016-12-29 | 2017-05-10 | 中国石油大学(华东) | Scanning type radioactive hole diameter measurement device and method |
Non-Patent Citations (5)
Title |
---|
Borehole and Invasion Effects of Formate-Based Mud Systems on LWD Density,Neutron,PE,and Gamma-rays Logs;P.Cooper 等;《SPE Annual Technical Conference and Exhibition》;20111030;第1-19页 * |
Standoff compensation and hole size correction of a new LWD density/neutron logging system;M Mickael 等;《SPE Technical Conference and Exhibition》;20090929;第1-15页 * |
基于超声测距的随钻井径测量系统设计;倪卫宁 等;《科技导报》;20130128;第31卷(第3期);第48-51页 * |
蒙特卡罗模拟研究水平井密度测井中岩屑层的影响;于华伟 等;《核技术》;20091010;第32卷(第10期);第751-755页 * |
随钻密度测井间隙对探测器晶体影响的蒙特卡罗模拟;朱頔 等;《测井技术》;20110820;第35卷(第4期);第319-324页 * |
Also Published As
Publication number | Publication date |
---|---|
CN108509675A (en) | 2018-09-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN105550448B (en) | Pre-drilling three-dimensional borehole modeling method and device based on drilling track design parameters | |
US9354050B2 (en) | Borehole characterization | |
US9057795B2 (en) | Azimuthal cement density image measurements | |
US20140052376A1 (en) | Method for Cement Evaluation with Acoustic and Nuclear Density Logs | |
RU2570221C2 (en) | Determining position of geologic horizon relative to manifestation of seismic pulse in seismic data | |
US10884158B2 (en) | Multi-barrier wellbore integrity inspection system with eccentricity correction | |
US8527204B2 (en) | Volume of investigation based density image processing | |
US20150331141A1 (en) | Geological Constituent Estimation Using Calculated Spectra Relationships | |
CN107227950B (en) | Method for evaluating integrity of actual drilling hole track | |
CN110940736A (en) | Rock mass mechanics parameter determination method and system for rock slope blasting excavation damage area | |
CN112145165B (en) | Microcrack-pore type reservoir dynamic and static permeability conversion method | |
CN108509675B (en) | Method for calculating hole diameter and clearance by density logging while drilling | |
Mandal et al. | A new monocable circumferential acoustic scanner tool (CAST-M) for cased-hole and openhole applications | |
US9568639B2 (en) | Borehole tool calibration method | |
CN106761666A (en) | A kind of four probes scattering gamma logging and the method and device of nonlinear data inverting | |
CN109001815B (en) | Acoustic curve correction method based on seismic and well diameter constraints | |
CN112946778B (en) | Method for early warning karst collapse based on underground water turbidity monitoring | |
CN113126155B (en) | Sandstone reservoir prediction method aiming at strong reflection influence distributed among coal rocks | |
CN113720745B (en) | Method for calculating porosity of carbon chip-containing clastic rock reservoir by geophysical well logging | |
CN106761667B (en) | Method and device for four-probe scattering gamma logging and linear data inversion | |
Wang et al. | A novel method for formation density measurement in cased wells | |
Fan et al. | A Well Cementation Evaluation Method by the Azimuthal Gamma Combination With the Acoustic Logging in Horizontal Well | |
Elahifar et al. | Determining the Accuracy of Ultrasonic Caliper Measurements for Real Time Drilling Application | |
Janus et al. | Measurement and Simulation of Flow in a Section of a Mine Gallery. Energies 2021, 14, 4894 | |
WO2023230105A1 (en) | Enhanced spine-and-rib process for evaluation of formation density |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |