Question

Bore hole survey means

• A. Measurement of Depth of bore hole
• B. Measurement of time taken to drill hole
• C. Measurement of deviation of bore hole
• D. Identification of properties of bore hole

Hint:

In surveying, the primary goal is to determine positions and paths.
Think of a borehole survey as creating a map of the hole's journey underground, not just measuring its length or what it passed through.
This is crucial for accurately locating the position of a mineral deposit intersected by the borehole.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the definition of the term "borehole survey" in the context of mining or geology.

Step 2: Detailed Explanation:
When a borehole is drilled, especially a deep one, it rarely follows a perfectly straight path.
It can deviate from its intended course due to various factors like the geology of the rock, drilling parameters, and the drill string's alignment.
A

borehole survey is the specific process of measuring the borehole's actual trajectory or path in three-dimensional space.
This involves measuring its deviation from the vertical (inclination) and its direction in the horizontal plane (azimuth) at various points along its depth.
While measuring depth (A) and identifying properties (D, known as logging) are also parts of borehole analysis, the term "survey" specifically refers to mapping the path and its deviation.

Step 3: Final Answer:
Borehole survey means the measurement of the deviation of the borehole from its planned trajectory.
This corresponds to option (C).