Halliburton Energy Services, Inc.

Paul Joseph Ganssle

Shriram Sarvotham

Songhua Chen

Krishna M Ravi

Peter James Boul

Chang S Shin

Various embodiments include nuclear magnetic resonance (MR) sensor array systems and methods are disclosed. One such system includes a downhole casing having at least one MR sensor array peripherally coupled to an outside of the casing. At least one MR sensor array can include an MR sensor configured to monitor a cement/fluid mix composition while the cement is setting.

Nuclear magnetic resonance sensors embedded in cement

Various embodiments include a method for generating a pulse for use in nuclear magnetic resonance (NMR) logging. One such method generates the pulse by adjusting one or more of pulse parameters including a pulse shape, a pulse amplitude, a pulse phase, and/or a pulse frequency. The generated pulse produces a substantially uniform nuclear spin saturation or nuclear spin inversion response from a fluid. A wait time between the pulse transmission and an echo that indicates spin equilibrium has been achieved is substantially equal to a Ttime indicating characteristics of the fluid.

Selective NMR pulse for downhole measurements

A magnetic resonance method includes providing a pulse sequence that affects different measurement regions in presence of a magnetic field gradient, the pulse sequence having multiple pulse shapes and multiple characteristic interecho intervals (TEs). The method also includes storing echo information resulting from the pulse sequence

Magnetic resonance systems and methods employing multi-shape pulse sequences for parallel measurements

An example pulse sequence for performing phase coherence order selection within a single transient acquisition includes an excitation pulse with a tip angle of 90&#xb0; and phase &#x3d5;A, followed by a train of N refocusing pulses with tip angles of 180&#xb0;, with the center of the first refocusing pulse occurring time &#x3c4; after the center of the excitation pulse, and the center of the nrefocusing pulse occurring at time (2n+1)&#x3c4; after the center of the excitation pulse. This causes a train of echoes to form at times 2nt after the center of the excitation pulse. In this example, the first refocusing pulse has phase &#x3d5;B, where \&#x3d5;B&#x2212;&#x3d5;A\=90&#xb0;, and each successive refocusing pulse () has a phase &#x3d5;&#x3b4; greater than the last refocusing pulse. This incremental change in pulse phase over the course of the echo train has the effect of aiabatically 'dragging' the echo phase around the unit circle in a predictable manner corresponding to the phase coherence order of the relevant signals.

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Houston, TX, United States of America

Paul Joseph Ganssle