LWD Azimuthal Resistivity Logging in Unconventional Formations
A new type of logging tool has been used commercially during the last four years for geosteering and formation evaluation. It is unique in providing a true Azimuthal measurement in real time, which helps in predictive geosteering and imaging of bed boundaries. Of significant interest, it is designed for the many independent DD and MWD service companies so they can provide a superior product at a very competitive day-rate to second- and third-tier operators.
Laterolog types of tools are capable of accurate measurement of resistivity from 0.2 – 20,000 ohm.meters, enabling calculation of hydrocarbon saturation and placement of the well in the "sweet-spot". The new tool is also able to detect approach to a distant formation, estimate the resistivity, and indicate the direction in real-time. It can also provide imaging of contrasting formations and calculation of relative dip and strike angles. The new service is called the Geo-steering Resistivity Tool (GRT).
The new tool has been used in the Bakken (North Dakota), Niobrara (Wyoming & Colorado), Bone Spring, Barnett and Wolfcamp (Texas), Montney (Alberta), Viking and Bakken (Saskatchewan), and the Mississippi Lime (Kansas & Oklahoma). It has also shown promise in Coal-Bed Methane (CBM) wells in the San Juan Basin (Colorado), and in Heavy-Oil fields in Alberta. Recently, successful drilling jobs in China have been run in the Tarim Basin, Sulige Tight Gas Sands and HuaChi field in Changqing. The tool is also being used in Western Siberia for re-entry drilling.
A description of the tool design, real-time geosteering display, and operation is presented. Some case-studies from North America and China will also be presented.
AAPG Search and Discovery Article #90207 © AAPG Geoscience Technology Workshop, Unconventionals Update, November 4-5, 2014, Austin, Texas