− | Gravity offers significant applications to petroleum exploration. Gravity measurements are affected by changes in rock density. Surface gravity surveys and subsurface surveys made with a [[borehole gravity]] meter are effective in locating faults and geologic structures with density contrasts to their surroundings. The borehole gravity meter has broad application, from locating [[porosity]] in wildcats or through casing in old wells to monitoring fluid changes in productive reservoirs. This chapter discusses the traditional application of gravity, from surface surveys to the application of borehole gravity measurements. | + | Gravity offers significant applications to petroleum exploration. Gravity measurements are affected by changes in rock [[density]]. Surface gravity surveys and subsurface surveys made with a [[borehole gravity]] meter are effective in locating [[fault]]s and geologic structures with density contrasts to their surroundings. The borehole gravity meter has broad application, from locating [[porosity]] in wildcats or through [[casing]] in old wells to monitoring fluid changes in productive [[reservoir]]s. This chapter discusses the traditional application of gravity, from surface surveys to the application of borehole gravity measurements. |