It hasn't always been this easy to take directional measurements while drilling a well, and that's to say nothing of vibration, gamma radiation, temperature, and rotation, among others. Before MWD/LWD, measuring just the basics was a laborious, time-consuming process that wasted countless dollars and hours at the drill site. Here's a brief history of MWD, a peek at how most MWD looks today, and what its like to be on the leading edge of independent MWD technology.
Measurement While Drilling (MWD), otherwise known as Logging While Drilling (LWD), is a system developed to perform downhole measurements and transmit relevant data to the surface and guide the drilling direction and process. At the most basic level, this data includes the wellbore (the hole) inclination from vertical and the magnetic direction from north. Using this information and basic trigonometry, a three dimensional plot of the well can be produced.
Prior to the introduction of early MWD/LWD technology in the 1970s, wireline logging was the global standard for obtaining survey data. The process for wireline logging included fully halting the drilling process, putting the drill pipe on slip, lowering the wireline tool, retrieving the tool, and reading the survey data before planning further action. Especially if the drilling process required multiple surveys, this had the potential to dramatically increase non-productive time (NPT).
Enter MWD. This new technology allowed for transmission of data through the mud stream with drilling halted for only a few minutes, eliminating the need to fully stop the drilling process and significantly increasing the efficiency of drilling operations. In addition, extreme well angles rendered traditional logging tools entirely ineffective, as they couldn’t be pushed through those angles to retrieve information. MWD technology, in being attached directly to the drill string, overcame this shortcoming and gained further traction in the 1980s with the increase in drilling that required such severe angles.
These days, MWD/LWD tools are able to transmit far more than directional data, and they’re able to do so far faster than previously possible. Real-time drill and directional data is now commonly accompanied by the measurement of gamma-ray emissions from the rock (to determine what type of rock formation is being drilled), rock density, porosity and fluid pressures (to determine how freely fluid can flow through the formation and the volume of hydrocarbons present). In addition to gyroscopes, magnetometers and accelerometers, advanced MWD tools make use of gamma ray sensors, temperature and pressure gauges, strain gauges, and more to measure the torque and weight on the bit, mud flow volume, downhole temperature, smoothness of drillstring rotation, and type/severity of downhole vibration.
This data is converted to binary code by an onboard logic unit, which then transmits the data to the surface using Mud Pulse Telemetry (MPT). A Pulser Unit on the tool varies the drilling fluid (mud) pressure according to the binary code. These pressure fluctuations are then decoded at the surface into usable data.
The leading edge of MWD technological innovation today is rife with longer-lasting tools, high-speed data transmission, and new sensors, along with survey accuracy heretofore impossible to achieve. NewTech MWD is the industry leader in supplying directional drilling companies with the newest, most advanced independently-manufactured MWD tools in the world, and has the expertise to provide you with not only the tools, but also the operational knowledge and support you need to join us at the forefront of MWD tech now and in the years to come.
Contact us today to learn more about how we can leverage these technologies to help you reduce uncertainty, boost efficiency and increase production.