A new large hole nuclear magnetic resonance logging while drilling tool for early stage formation evaluation
Speaker: Nate Bachman, Schlumberger
Date: Wednesday March 8th , 2017
Time: Presentation starts at 12:00 pm. Lunch is served at 11:30 am.
Cost: Regular: $15; Student: $10
Pre-online registration is required!
Address: Weatherford Lab, 5200 North Sam Houston Parkway West Suite 500 Houston, TX, 77086.
Parking: One story building with surface parking. Visitors are requested to reverse park, note their license plate number and sign in at the main reception.
Sign-in process: Enter the building through the main entrance (it is the doors with the big Weatherford sign above them). Visitors will then be directed to the conference/media room.
A new8.25 inch LWD NMR logging tool which operates in high flow rates and large boreholes, while maintaining short echo spacing and high vertical resolution, has been recently introduced. This paper documents the tool performance in a variety of lithologies, mud types, and hydrocarbon types and shows the benefits of real-time formation evaluation using LWD logs in Ecuador and the Gulf of Mexico. Job planning and log quality control of the new tool will also be discussed.
Case 1 was logged in a 12.25 inborehole drilled with WBM in Ecuador for rock quality and pay identification. A previously unknown hydrocarbon zone was identified with the help of LWD NMR. This unknown pay zone turns out to be the best of all other known pay zones, adding considerable new reserves to the field. Both carbonate and sandstone formations were present, and core analysis showed an excellent match to the while-drilling logs for both porosity and permeability. In this complex lithology, the NMR lithology-independent porosity was an essential part of the early-time evaluation. An advanced workflow based on principal component analysis was applied to the entire depth log of T2 distributions for both facies and hydrocarbon detection. Identification of the principal component attributable to oil allowed for a continuous viscosity estimate as a function of depth.
Case 2 comprised multiple wells logged in a 12.25 inborehole drilled with OBM for a deep water campaign along the Gulf of Mexico in the Tertiary geological system. The logging program was designed to evaluate the potential of the reservoirs in real time. The LWD NMR tool was run successfully in deviated well sections along with formation pressure, sonic, and density neutron while drilling tools. This combination enabled an understanding of the flow potential of the reservoir, and the real time logs allowed for optimization of the formation pressure points. The LWD NMR data also aided in optimizing the Wireline logging program.
The data provided by the new LWD NMR tool adds valuable insight into the porosity, rock quality, hydrocarbon properties and producibility of reservoirs at the earliest stages of exploration and development drilling.High resolution LWD NMR data during early exploration is well suited for principal component analysis, which is highlighted in this paper.
H. Nate Bachman is principal physicist and project manager at the Schlumberger Houston Formation Evaluation Center. He received a BS degree in physics from Valparaiso University, Indiana, USA, in 1993 and a PhD in physics from Northwestern University, Illinois, USA. From 1999 to 2002 he held a research associate position at Harvard University, Massachusetts, USA. Nate has worked on both research and engineering projects relating to NMR logging tools and applications, including 2 years of research at the Dhahran Carbonate Research Center in Saudi Arabia. Nate is a member of SPE, SPWLA, and the American Physical Society.