Nuclear Magnetic Resonance Comes Out of Its Shell
Ridvan Akkurt Saudi Aramco
Dhahran, Saudi Arabia
H. Nate Bachman Chanh Cao Minh Charles Flaum Jack LaVigne Rob Leveridge Sugar Land, Texas, USA
Romulo Carmona Petróleos de Venezuela S.A. Caracas, Venezuela
Steve Crary Al-Khobar, Saudi Arabia
Eric Decoster Barcelona, Venezuela
Nick Heaton Clamart, France
Martin D. Hürlimann
Cambridge, Massachusetts, USA Wim J. Looyestijn
Shell International Exploration and Production B.V. Rijswijk, The Netherlands
Duncan Mardon
ExxonMobil Upstream Research Co. Houston, Texas
Jim White Aberdeen, Scotland
Oilfield ReviewWinter 2008/2009: 20, no. 4. Copyright © 2009 Schlumberger.
AIT, CMR, MDT, MR Scanner, OBMI and Rt Scanner are marks of Schlumberger.
MRIL (Magnetic Resonance Imager Log) is a mark of Halliburton.
Petrophysical evaluation involves a lot of science and a bit of art. The scientific basis of a new measurement technique often develops from step changes in technologies. The art of application sometimes plays catch-up while interpretation tools are developed to fully exploit new measure - ments. Attempts to integrate new forms of data into existing workflows may be met with resistance by those skeptical of the added value of the new information. In addition, the learning curve inherent in adopting new concepts is often steep, which can be at odds with the time demands of busy geologists and petrophysicists. Nuclear magnetic resonance logging is an example of the physics of measurement—the science—being understood and developed before petrophysical analysis—the art—integrated the measurements into standard workflows. Although NMR was initially introduced in the 1960s, it took 30 years to develop an NMR acquisition tool that could deliver the information that physicists knew was available. The first successfully deployed pulsed-NMR tool was introduced in the early 1990s by the NUMAR Corporation, now a subsidiary of Halliburton. Equipped with
permanent, prepolar izing magnets, these logging tools use radio frequency (RF) pulses
to
manipulate the magnetic properties of hydrogen nuclei in the reservoir fluids. Schlumberger followed soon after with the CMR combinable magnetic resonance tool.
In general, NMR measurements were not accepted enthusiastically because the data did not always assimilate well with existing inter - pretation schemes. However, early adopters found applications for the new measurement, and, as tools evolved, petrophysicists established the value of NMR logging to the interpretation community—creating an expanding niche in the oil and gas industry. Today, most service companies offer some form of NMR logging tool, and LWD NMR tools have been developed to provide reservoir-quality information in real time or almost real time.
Magnetic resonance tools measure lithology- independent porosity and require no radioactive sources. They also provide permeability estimates and basic fluid properties. Initially, the fluid properties were limited to free-fluid volume and immovable clay- and capillary-bound fluid
Advances in measurement technology, along with improved processing techniques, have created new applications for nuclear magnetic resonance (NMR) logging. A new NMR tool delivers conventional NMR-based information as well as fluid-property characterization. These NMR data identify fluid types, transition zones and production potential in complex environments. Placing this information into multidimensional visualization maps provides log analysts with new insight into in situ fluid properties.
4
Oilfield Review
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72