Page 56 - Drilling Technology in Nontechnical Language

Chapter 3 – DRILLING A LAND EXPLORATION WELL 47

General information

General information included in a drilling program includes the
following:
1. Which country, which exploration block (blocks are usually
numbered), name of drilling rig, program issue date, who the
program was written by, and who approved it
2. Which offset wells were used for data input
3. A statement on shallow gas (e.g., whether likely to be present
or not)

Well objectives

It is important to differentiate between primary objectives (those that
the well must meet) and secondary objectives (those that are desired if they
can be obtained for little extra effort or cost).
A graph is normally given, showing the anticipated well depth at each
day of the operation. The actual progress can be plotted on the same graph,
to show whether the well is on target, behind the curve (late), or ahead of

the curve (early). The flat spots on the graph show where drilling stops to

run casing into the well at the end of each hole section (fig. 3–7).

Fig. 3–7. Graph of time vs. depth for an example well

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