Changes

* In many basins, BCGAs occur at depths greater than 10,000 ft (3048 m). Artificial stimulation at these depths is difficult and expensive. Although there have been significant improvements in drilling and completion technologies within the past 20 yr, continued advances in technologies are essential to tap the very large gas resources at these depths.

* In many basins, BCGAs occur at depths greater than 10,000 ft (3048 m). Artificial stimulation at these depths is difficult and expensive. Although there have been significant improvements in drilling and completion technologies within the past 20 yr, continued advances in technologies are essential to tap the very large gas resources at these depths.

* In thick, gas-saturated reservoirs containing interbedded water-bearing reservoirs, improved techniques are needed to discriminate between gas-bearing and water-bearing reservoirs.

* In thick, gas-saturated reservoirs containing interbedded water-bearing reservoirs, improved techniques are needed to discriminate between gas-bearing and water-bearing reservoirs.

* The integrity of capillary pressure seals over long periods of geologic time needs to be determined.

* The integrity of [[capillary pressure]] seals over long periods of geologic time needs to be determined.

* More geologic research into the occurrence of BCGAs, especially indirect types, is desirable. Essentially no information is available concerning the nature of or exploration strategies for indirect BCGAs.

* More geologic research into the occurrence of BCGAs, especially indirect types, is desirable. Essentially no information is available concerning the nature of or exploration strategies for indirect BCGAs.

* Methods of identifying and characterizing natural fractures must be improved.

* Methods of identifying and characterizing natural fractures must be improved.