Schlumberger Technology Corporation

Gabriela Leu

Yi-Qiao Song

Krishnamurthy Ganesan

Nicholas J Heaton

Martin D Hurlimann

Soumyajit Mandal

Ravinath Kausik Kadayam Viswanathan

Pabitra N Sen

Anatoly Dementyev

Thomas J Neville

Payam Tabrizi

Nicholas Drenzek

Van D M Koroleva

A method for measuring one or more properties of a formation includes applying a magnetic field to a subterranean formation using a downhole tool. A radiofrequency signal is transmitted into the subterranean formation that is exposed to the magnetic field. The radiofrequency signal induces a transverse magnetization in the subterranean formation, and the transverse magnetization induces an initial voltage signal in the downhole tool. The initial voltage signal is amplified using a first amplifier in the downhole tool such that the first amplifier outputs a first amplified voltage signal. The first amplified voltage signal is introduced to an input of the first amplifier, such that the first amplifier amplifies the first amplified voltage signal and outputs a second amplified voltage signal.

Active damping for NMR logging tools

An arrangement for shielding an NMR tool from electromagnetic noise, having a nuclear magnetic resonance tool configured to send and receive signals, a first shield configured around a nuclear magnetic resonance antenna of the nuclear magnetic resonance tool and a second shield configured to reduce the effects of eddy currents in the first shield.

Composite noise shield for magnetic resonance tools

Systems and methods for magic angle spinning nuclear magnetic resonance analysis of samples from unconventional reservoirs are described. Fast and inexpensive methods are described that can provide reliable information on TOC content, type, and maturity (via the relative abundances of different hydrocarbons, for example) without the need for more extensive sample preparation or destruction. If care is taken during sample recovery and storage, NMR can also yield an estimate of gas-in-place, including detailed typing (e.g. methane vs. ethane). The described MAS NMR analysis is used to determine various properties of unconventional reservoirs, including gas and oil shales, which are useful in evaluating their worth and producibility.

NMR analysis of unconventional reservoir rock samples

Growing community of inventors

Richmond, TX, United States of America

Gabriela Leu