Changes

==Monitoring well drawdown==

==Monitoring well drawdown==

[[file:applying-gravity-in-petroleum-exploration_fig15-14.png|thumb|{{figure number|3}}. Copyright: ARCO Exploration and Production Technology, 1997.]]

[[file:applying-gravity-in-petroleum-exploration_fig15-14.png|left|thumb|{{figure number|3}}. Copyright: ARCO Exploration and Production Technology, 1997.]]

One of the most attractive aspects of borehole gravity applications is its ability to detect gas, oil, and water contacts at large distances from the borehole. It can do this through multiple casing strings and formation damage—conditions where the neutron density tool performs poorly. In many hydrocarbon reservoirs, the oil has a gas cap. Frequently, these reservoirs have an underlying water zone. The shape of these interfaces over time is critical to production strategy. Methods can determine where those contacts exist in the well-bore, but only borehole gravity can determine their shape away from the well. Because the interfaces are mobile with time, their movement can be monitored with borehole gravity.

One of the most attractive aspects of borehole gravity applications is its ability to detect gas, oil, and water contacts at large distances from the borehole. It can do this through multiple casing strings and formation damage—conditions where the neutron density tool performs poorly. In many hydrocarbon reservoirs, the oil has a gas cap. Frequently, these reservoirs have an underlying water zone. The shape of these interfaces over time is critical to production strategy. Methods can determine where those contacts exist in the well-bore, but only borehole gravity can determine their shape away from the well. Because the interfaces are mobile with time, their movement can be monitored with borehole gravity.