Abstract Drilling Gravimetric Gradiometry is becoming an increasingly common technique to help understand the subsurface in the oil and gas industry. It can be combined with other techniques and well logs to form a very in-depth interpretation of the target formations. The development and methodology of drilling gravimetric gradiometry and how it can be used in downhole applications are explained along with the advantages and disadvantages of this method. IntroductionGravimetric gradiometry is a widely used technique for drilling applications. surface in the oil industry, but its use as a downhole tool offers a new way to study the borehole and allows for better resolution in projects such as reservoir monitoring. Surface gravimetric gradiometry applications have been successful in monitoring reservoir activity with flooding operations, but borehole gravimetric gradiometry would overcome the investigation depth limitations of surface surveys (Neill, 2010). Downhole gradiometry also provides a deeper depth of investigation than nuclear measurements such as gamma ray tools. History and development The first underground measurements of gravity were made in England by Airy (1865) who used pendulums to measure the vertical gravity gradient between the top and bottom of a vertical tree (McCulloh, 1965). Gravity gradiometry was also the first geophysical study applied to petroleum exploration. This was carried out in 1915 at the Egbell oil field in Slovakia, but it was only a surface survey using a torsion balance (Neill, 2010). A torsion balance is a pendulum designed by Hungarian physicist Baron Loránd Eötvös (1848-1919) that measures the density of the underlying rock. From 1915 to 1936, this technique was used quite extensively for geophysiology...... middle of paper ......ell Log Analysts (SPWLA) (1968): n. page. Web. Neill, Francis. “Potential of downhole gravimetric gradiometry for reservoir management.” » World Oil 231.1 (2010): n. page. Global Oil Online. Internet. March 5, 2014. Nekut, AG “Drilling Gravimetric Gradiometry.” Geophysics 54.2 (1989): 225. SEG. Internet. April 17, 2014. Nind, Chris JM and Jeffery D. Macqueen. "The borehole gravimeter: development and results." Kochi 2013 (nd): n. page. Internet. March 5, 2014. Rim, Hyoungrea and Yaoguo Li. "Single-hole imaging using borehole gravimetric gradiometry." Geophysics 77.5 (2012) : G67-76. SEG. Internet. April 17, 2014. Seigel, C. Nind, R. Lachapelle, M. Chouteau and B. Giroux. ground and drilling: Proceedings of Exploration 07: Fifth Decennial International Conference on Mineral Exploration (2007): 1143-147 Internet..