Monday, July 16, 2007

Marathon Tries New Drilling Approach, Dunn Co.

Marathon has received permission to drill two separate horizontal wells on the Beck lease in secs. 5 and 8, T.146, R.94 in Bailey Field, Dunn Co. The field rules currently allow only one horizontal well per1280 acre unit. Marathon doesn't know if two wells are necessary to effectively drain a 1280 unit, but it thinks the plan will probably be economic, and the company plans to drill the first well and then skid the rig the few feet to the other surface location. The most important aspect of this strategy is that it will also allow the company to better utilize currently available completion and stimulation procedures then if dual laterals were drilled from a single vertical wellbore.

Marathon also has an application pending for a two well per drilling unit project just to the southw
est in secs. 18 and 19. Marathon also received permission for five 1280 acre drilling units to the east of Bailey Field in the eastern part of T.146, R.93 and the extreme northwestern part of T.145, R93. The company also has an application pending for an additional four 1280 acre drilling units scattered in T.144, R94, T145, R.92, and T.145, R.94.

Marathon currently has three rigs drilling in the area. It's fourth rig that is drilling in Mountrail Co. is expected to move to a two mile west stepout to Murphy Creek Field and drill in secs. 5 and 8 of T.144, R.96, in the near future (see map, 3/20 post).


Anonymous said...

Two legs in a 1280 doesn't seems like there effectivly draining the oil. How much protest is there to this practice and what are the reasons for doing it?

Teegue said...

The only party I can see that would have a problem with it is the other working interest owners who have to share in the costs. As for the mineral owners, I'm sure they are elated as most all the companies are using only one lateral per drilling unit, whether that be 640 or 1280 acres. (Nobody protested this particular plan).

These wells are very expensive and it isn't really a question of draining all the oil, but more of a question how much is economic to drain. Nobody is going to shell out another five million for a second lateral well if they are only going to get a million dollar return on that investment. The reservoir quality of the Bakken is terrible and can vary greatly from section to section. There is no guarantee that any one well will pay its expenses. A lot of the single lateral wells will never pay out, so there is certainly no incentive to add the cost of an additional lateral. Oil companies don't have an obligation to drain all the oil, the only duty they have is to act as a reasonably prudent operator would under similar circumstances, however, it is in their own economic interest to drain as much as they can after they incur the costs of drilling a well.

As for why they are they are doing this, they could do the same well configuration from a single vertical well, but they are drilling two vertical wells (which adds about another million dollars in costs) so they can better use their frac technology, because companies have had problems with managing that when using dual laterals from a single vertical well bore. Marathon apparently thinks they can recover enough additional oil to justify the costs. Other companies I'm sure feel differently. In five years from now there will be enough data to see whose ideas worked better.

This is just a test phase for this approach and Marathon may well continue drilling single laterals in their units if they determine that the dual laterals are not recovering enough additional oil to make them pay out.