Technology — 21.07.2026 — East West Drilling engineering team
MWD (Measurement While Drilling) is a sensor package located inside the drill string, close to the bit, measuring inclination, azimuth and tool face orientation. LWD (Logging While Drilling) adds real-time formation properties on top of that — radioactivity, resistivity, porosity. Together they give the drilling crew a kind of "vision" — instead of moving through a dark room, the crew knows what lies ahead.
Data usually reaches the surface via mud-pulse telemetry: the tool creates pressure variations in the mud column to send a binary signal, which a surface decoder converts back into readable data. The delay can be a few minutes, but that is fast enough for real-time decisions.
The main benefit of this data is catching small deviations early by comparing the actual path against the plan. The longer a deviation goes unaddressed, the sharper the correction angle has to be — costing more time and adding stress to the string. Real-time measurement, by contrast, catches deviation in centimetres, allowing small, inexpensive corrections that keep the well on target.
LWD's geological data also enables a technique called geosteering — adjusting the trajectory in real time to keep it within the productive zone. This is especially valuable in thin or dipping reservoirs, where it maximises the well's contact with the productive interval.
