MT/T 1042-2007Quality Standard of Drill for Coal Geology Exploration (English PDF)

3.1 Quality standard of drilling coal-seam

The quality of drilling coal-seam can be divided into 3 levels, such as high-quality, qualified, and unqualified; the quality indicators of various levels can refer to Table 1.

Table 1 – Quality Indicators of Drilling Coal-seam

Item High-quality Qualified Unqualified

Thickness of coal-seam

Satisfy one of the following conditions:

1. The sum of the missing coal-cores in the initial coal (top) and final coal (bottom) is no more than the following provisions:

Satisfy one of the following conditions:

1. The sum of the missing coal-cores in the initial coal (top) and final coal (bottom) is no more than the following provisions:

Unqualified products indicate those products that are not qualified

True thickness of coal- seam / m

Sum of missing amount / m

True thickness of coal- seam / m

Sum of missing amount / m c) Drill collapse, blockage, or sediment in it bury the thickness of the major water- bearing-layer exceeding 1/5.

d) Q-S curve is abnormal; can’t be interpreted or utilized.

5.2 Quality standard of drill constant-flow unstable flow pumping test

The quality of drill constant-flow unstable flow pumping test can be divided into 4 levels, such as high-quality, qualified, unqualified and abandoned.

5.2.1 Quality standard of high-quality, qualified and unqualified of drill constant-

flow unstable flow pumping test

The quality standard of high-quality, qualified and unqualified of drill stable flow pumping test can refer to Table 6.

5.2.2 Other conditions

The high-quality and qualified levels of drill constant-flow unstable flow pumping test shall also satisfy the following conditions:

a) The water stopping effect is checked to be qualified; the quality of washing hole is reliable.

b) The sediment in the hole shall not bury 1/5 thickness of the major water-bearing- layer.

c) The water samples shall be taken as per the sampling requirements.

d) The observations of the static water-level and restored water-level shall conform to the provisions of the regulations.

e) The original data shall be recorded timely, correctly, tidy; the writing shall be clear, correct, and unmodified.

5.2.3 Abandoned hole

It belongs to the abandoned hole once the quality of drill constant-flow unstable flow pumping test is one of the following cases:

a) The water drawn from the drill penetrates into the hole in the vicinity of it, forming a circulating water.

b) Sealing and water stopping fails; and there are not the effective flow logging data for remedy.

c) Drill collapse, blockage, or sediment in it bury the thickness of the major water- bearing-layer exceeding 1/5.

g) The completeness and rationality of the drawdown, time (distance) semi- logarithm or logarithm curve of unstable flow pumping shall be audited according to the pumping objectives and data interpretation.

h) In addition to as per the above requirements in Table 6, the other pumping quality standard shall conform to the provisions of Regulation on Coal Resources

Geological Exploration Pumping Test.

i) When the buried depth of the water-level is greater than 150m, and water volume is large. If the existing pumping equipment can’t meet the requirements of water- level drop in Tables 5 and 6, the acceptance shall be conducted as per the approved design comments.

6.1 Quality standard of drill comprehensive coal-seam

The quality of drill comprehensive coal-seam can be divided into 3 levels, such as high- quality, qualified, and unqualified.

6.1.1 Quality standard of the high-quality layer of the drill comprehensive coal-

seam

Through the comparative study of the drilling and logging data, it belongs to the high- quality coal-seam when meeting one of the following conditions:

a) The depth, thickness of coal-seam, coal-core mining and original records shall satisfy the quality standard of high-quality layer of drilling coal-seam;

b) The quality of logging coal-seam shall satisfy the standard of high-quality layer;

the coal-core length mining rate and weight mining rate of the design sampling coal-seam shall meet the requirements of drilling high-quality layer.

6.1.2 Quality standard of qualified layer of drill comprehensive coal-seam

Through the comparative study of the drilling and logging data, it belongs to the comprehensive qualified coal-seam when meeting one of the following conditions:

a) The depth, thickness of coal-seam, coal-core mining and original records shall satisfy the quality standard of qualified layer and above of drilling coal-seam;

b) The quality of logging coal-seam shall satisfy the standard of qualified layer; the coal-core length mining rate and weight mining rate of the design sampling coal- seam shall meet the requirements of drilling qualified layer.

6.1.3 Quality standard of unqualified layer of the drill comprehensive coal-seam

Appendix A (Informative)

Major Data List of Drill of Coal Geological Exploration

A.1 Drilling and measuring notice

A.2 Drill specifications

A.3 Notice on modification of drill design

A.4 Notice on drill commencement

A.5 Report on original record shift of drilling (including record contents of

simple hydrological observation)

A.6 Drilling gauge measurement table

A.7 Advance notice on coal-finding in drill

A.8 Report on coal-mining in drill

A.9 Sampling instructions of drill rock-coal sample

A.10 Drill rock-core identification table (original and copy)

A.11 Notice on stopping drilling

A.12 Notice on drill logging

A.13 Original record table of drill yield logging

A.14 Result table of site interpretation of drill logging

A.15 Result table of drill slope-measuring

A.16 Result table of drill temperature-measuring

A.17 Drill sealing specifications

A.18 Drill sealing report

A.19 Result and quality rating table of drill coal-seam logging

A.20 Result table of logging interpretation of drill geological section

A.21 Result and quality rating table of drill coal-seam comprehensive use

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