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Question
If a client drills down to 1500' MD and takes single shot surveys every 500' Inclination only and lets say @ 1500'MD / 0.65 Inc / 178 Az. At low angles Azimuth is not a factor right?
At what Inclination does Azimuth matter or accurate?
Gyro is really the only way to get a TRUE Inclination and Azimuth right?
Under lets say 1.5 Inclination any azimuth could be used because its all just a guess unless they drop a gyro right?
I have always heard that anything under 1 of inclination azimuth is not a factor use the azimuth of the direction the planned wellbore is going, is this a good practice in your opinion?
Thanks for any help you can give me.

Answer
The reason the Azimuth doesn't matter much at low angles is because there is little or no horizontal displacement until the Inclination starts to build.  Sometimes you can get accurate readings with MWD at low angles, but other times the steel pipe collars above the MWD collars (which are made of non-mag stainless) will interfere with one or more of the magnetometers in the MWD tool.  It just depends on the well path and also the vicinity of any other wells in the same area.  When drilling offshore from a platform sometimes it will take several hundred feet to clear the other wells drilled from the platform.  I agree with you that if the Inclination is under ~ one degree then the Azimuth will not matter very much.  Typically when the well is kicked off the well path will need to be turned/steered to the proper Azimuth once the Inclination starts to stay above one degree consistently.

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David Traugott

Expertise

I can answer questions related to the technical issues associated with the drilling and completing of oil and gas wells; very familiar with the cementing process, LWD tools and Coiled Tubing operations. Limited knowledge of mineral rights and/or royalties.

Experience

Seventeen years working as an engineer in the industry both in the field and in the office. Field locations include offshore, land, and overseas. Office locations include Lafayette, LA and Houston, TX.

Organizations
SPE, AADE, IADC, API, IEEE, ICoTA

Publications
SPE Drilling and Completion Magazine, World Oil, Harts E&P.

Education/Credentials
Bachelor of Science in Electrical Engineering, UL Lafayette 1995. Strategic MBA, University of Houston-Victoria 2010

Past/Present Clients
Major and Independent Oil and Gas Companies.

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