Home Page Home Page
Advanced Search  Site Map  
What's NewMedia CentreIndustry IssuesAbout UKOOAEducation

Britain's Offshore Oil and Gas Index Britain's Offshore Oil and Gas Index Next Section Next

BRITAIN'S OFFSHORE OIL & GAS

*Getting the Most out of a Well


F74: Wireline logging

Vital information on the type of rock drilled and the fluids it contains often needs to be obtained either while actually drilling, or after drilling before running casing (F74). This is obtained by running electronic measuring devices into the well - either while drilling (as part of the drillstring) or after drilling on "wireline" (F73). The various types of measurement include: (1) electrical resistivity of fluids within the rock; (2) the speed of sound through the rock; (3) reaction of the rock to gamma ray bombardment; (4) production of gamma rays from fluids within the rock due to neutron bombardment; and (5) natural gamma radiation of the rocks. The data obtained give indications of rock type and porosity and the presence of oil or gas.

Other devices measure hole diameter, dip of strata and the direction of the hole. Sidewall corers which punch or drill out small cores of rock, geophones for well velocity surveys and seismic profiling are also lowered into uncased wells. In deviated wells approaching the horizontal, flexible high-pressure steel coiled tubing may be used to carry wireline logging tools and for performing wellbore maintenance operations.

F73: Wireline logs





If oil or gas has been detected in a well, a tool is lowered on a wireline to measure fluid pressures and collect small samples. If the flow rate of the well needs to be measured, a "well test" is carried out. This involves running production tubing with flow control valves and isolation packers into the well, then flowing the hydrocarbons to surface through the high pressure pipework containing pressure recorders and flowmeters.



Britain's Offshore Oil and Gas Index Britain's Offshore Oil and Gas Index Next Section Next

Home What's New Media Centre Industry Issues About UKOOA Education

© 2002 United Kingdom Offshore Operators Association
London: Tel 020 7802 2400  Fax 020 7802 2401    Aberdeen: Tel 01224 577 250  Fax 01224 577 251
Email info@ukooa.co.uk  Web http://www.oilandgas.org.uk/

Legal and Copyright Issues and Privacy Statement