

FOR IMMEDIATE RELEASE               Contact:  Guy T. Marcus
September 30, 1997                            Vice President-Inv. Rel.
                                              (214) 978-2691


                   HALLIBURTON COMPLETES ACQUISITION OF NUMAR


         DALLAS, Texas -- Halliburton Company (NYSE:HAL) announced today that it
completed  the  acquisition  of  NUMAR  Corporation   (NASDAQ:NUMR)  immediately
following NUMAR's special meeting of shareholders where the merger was approved.
         Under  terms of the  agreement  and  plan of  merger  Halliburton  will
exchange  0.9664 of a share of its common stock (after  giving  effect to a July
21,  1997  2-for-1  Halliburton  common  stock  split)  for each share of NUMAR.
Halliburton will issue  approximately 8.2 million shares of its common stock for
all of the NUMAR common stock and about  900,000  shares of  Halliburton  common
stock will be reserved for future issuance upon exercise of NUMAR options.
         NUMAR designs,  manufactures,  and markets a patented, proprietary well
logging device, the Magnetic  Resonance Imaging Logging  ("MRIL(R)") tool, which
utilizes  magnetic  resonance  imaging   technology,   widely  used  in  medical
diagnostic   imaging  devices,   to  evaluate   subsurface  rock  formations  in
newly-drilled  oil and gas wells.  The MRIL(R) tool is a  commercially-available
well logging tool able to measure, in real time at the wellsite,  the proportion
of fluid that is free to flow within a
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Halliburton Company                         2


formation, effective formation porosity, fluid viscosity and rock grain size, to
perform  direct   hydrocarbon   typing   ("DHT(R)")  and  to  derive   formation
permeability.  Further, a new application  introduced in 1996, allows MRIL(R) to
identify clay bound water and thus determine total porosity.
         Dick  Cheney,  Halliburton  Company's  chairman  of the board and chief
executive  officer,   said,  "NUMAR's  MRIL(R)  technology  represents  a  major
breakthrough  to improve  open hole  wireline  logging  services  for  customers
worldwide.  The  MRIL(R)  technology  is now  being  applied  to  only  a  small
percentage  of wells drilled and future growth  opportunities  are  significant.
Halliburton  plans  to  provide  its  extensive  worldwide   infrastructure  and
resources  to  accelerate  the  application  of NUMAR's  MRIL(R)  technology  to
worldwide opportunities."
         Cheney also said, "NUMAR will continue as a wholly-owned  subsidiary of
Halliburton  Company and become part of the company's  Energy Services  business
segment.  NUMAR will continue to be headquartered  in Malvern,  Pennsylvania and
its  management  team will remain in place with Dr. Melvin Miller  continuing as
president."
         Halliburton  Company is one of the world's largest  diversified  energy
services, engineering, maintenance, and construction companies. Founded in 1919,
Halliburton  provides a broad range of energy  service and products,  industrial
and marine engineering and construction services.

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