Changes

* ''Determination of coring points''—Prediction of lithology ahead of the bit is critical when selecting prospective intervals for coring. With MWD log data, the geologist can obtain a more reliable correlation and can select core points with more confidence. This reduces the risk of missing critical formation tops or coring intervals that are not essential for geological or reservoir evaluation.

* ''Determination of coring points''—Prediction of lithology ahead of the bit is critical when selecting prospective intervals for coring. With MWD log data, the geologist can obtain a more reliable correlation and can select core points with more confidence. This reduces the risk of missing critical formation tops or coring intervals that are not essential for geological or reservoir evaluation.

* ''Selection of optimum casing and total well depths''— Accurate and timely selection of casing and total well depth become extremely important when the possibility of penetrating abnormally pressured zones exists. This condition often requires extra rig time to circulate and condition the drilling mud or, in the worst case, results in drill pipe sticking and expensive [[fishing]] operations (see “[[Fishing]]”).

* ''Selection of optimum casing and total well depths''— Accurate and timely selection of casing and total well depth become extremely important when the possibility of penetrating abnormally pressured zones exists. This condition often requires extra rig time to circulate and condition the drilling mud or, in the worst case, results in drill pipe sticking and expensive [[fishing]] operations.

* ''Determination of kick-off point(s) for sidetrack wells''—The decision to sidetrack or redrill a well to a more favorable location can be made immediately if MWD data show the objective section to be poorly developed, faulted out, or drained. This often results in considerable cost savings by preventing unnecessary drilling below the objective interval and by eliminating the need for wireline logs.

* ''Determination of kick-off point(s) for sidetrack wells''—The decision to sidetrack or redrill a well to a more favorable location can be made immediately if MWD data show the objective section to be poorly developed, faulted out, or drained. This often results in considerable cost savings by preventing unnecessary drilling below the objective interval and by eliminating the need for wireline logs.

* ''Determination of kick-off point(s) for horizontal wells''— MWD logs are used for correlation with offset data and for directional planning in complex horizontal wells. With real time information obtained near the bit, borehole deviation and azimuth are continuously monitored and corrected to obtain the optimum angle of penetration. This helps ensure that the horizontal wellbore stays on target and within the desired reservoir interval.

* ''Determination of kick-off point(s) for horizontal wells''— MWD logs are used for correlation with offset data and for directional planning in complex horizontal wells. With real time information obtained near the bit, borehole deviation and azimuth are continuously monitored and corrected to obtain the optimum angle of penetration. This helps ensure that the horizontal wellbore stays on target and within the desired reservoir interval.