S
ince the first acid bottle survey systems were invented in
the late 1800s, there has been a significant push to provide
increasingly accurate and reliable methods of acquiring
downhole survey data, while decreasing the amount of time
it takes to obtain this information. As a result of this research
into new methods and technologies, there is now an increasing
number of evaluation options to help the drilling community
meet their operational needs: measurement while drilling (MWD)
tools with pulser drivers, electromagnetic (EM) transmission, and
numerous variations in between that have become mainstays in
the oil and gas industry.
However, when narrowing the scope of application to
vertical sections of wells – whether they are vertical wells or
the vertical section of a directional or extended-reach lateral
well – the need for traditionally high-priced, MWD-based tools
decreases significantly, as the data needed (inclination and/or
azimuth) is only one aspect of the tool’s full array of capabilities
(which include continuous transmission of gamma, shock, and
vibration). In addition, should there be little to no formation push
or drifting of the wellbore from vertical, the value gained from
using any of the high-output MWD tools becomes an exercise in
increasingly diminishing returns.
A secondary, yet equally important area to consider in today’s
drilling environment is the increased proliferation of pad drilling.
Pad drilling, which is the process of drilling multiple wellbores
from a single surface location, has gained increased attention
DRIVING
DOWNHOLE
SURVEYS
Michael Gaines, NOV, USA, demonstrates how the use of advanced bottomhole
assembly tools benefits the drilling community.
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