Demand for logging and measuring services in oil and natural gas drilling operations is projected to climb 4.7 percent per year through 2019 to $6.2 billion. Demand growth in the logging and measuring services segment will outpace overall drilling services demand due to the increasing need for downhole information in order to maximize well productivity and to reduce the chances of costly interruptions to drilling when problems arise. Although logging-while-drilling (LWD) and measurement-while-drilling (MWD) services will see fairly rapid growth, the use of LWD services rather than cheaper wireline logging will continue to be cost prohibitive in many onshore wells, and wireline logging will continue to hold a significant share of the market.
Logging and measuring services provided by oilfield services companies or specialized contractors allow drillers to gather data about the conditions of the drillstring or formation during drilling operations. These services give drillers the information necessary to optimize well placement, reduce or avoid problems during drilling, and properly design the well completion.
Logging generally refers to information gathered about the formation—such as its electrical resistivity, gamma radiation properties and porosity—while measuring refers to data collection regarding the position and trajectory of the wellbore. As such, MWD is an integral aspect of directional drilling and has played an important role in the growth of horizontal drilling and unconventional resource development. LWD is applicable to all types of wells, but its use is justified only when the other costs of well drilling are high.
Wireline logging will continue to account for a substantial share of the logging services market with more than 35 percent of total demand in 2019. In addition to the modest increase expected in the number of wells drilled annually through 2019, demand for wireline logging services will benefit from advances in computer interpretation of the collected data, which will increase the value of logging services to well operators and drillers. Wireline logging is a well-established technology and is itself comparatively inexpensive. However, it requires removing the drillstring from the well, an expensive process. As a result, when drilling wells with high daily drilling costs (such as in offshore drilling), the total cost of wireline logging can be greater than that of LWD, which does not require that the drillstring be removed.
MWD and LWD services are related to wireline logging in that they involve downhole information gathered using complex instruments. The difference is that in MWD and LWD, the data is collected by instruments on the drillstring and measured as the well is drilled. This real-time data collection is extremely valuable as it allows the driller to make adjustments as the well is being drilled, as opposed to doing so only periodically after wireline logging is run.