Otto Energy mulls South Marsh Island F5 sidetrack

March 23, 2020

Otto Energy Ltd. and its Gulf of Mexico South Marsh Island 71 partner will temporarily abandon the F5 wellbore in a manner that allows for a possible sidetrack when uncertainty from the COVID-19 pandemic dissipates and a time where oil price volatility stabilizes.

Drilling operations on F5 were resumed Mar. 17 by Enterprise Offshore Drilling’s Enterprise 264 jackup. Surface casing shoe was tested at 3,610 ft measured depth (MD) and the well reached 8,505 ft MD (7,591 ft true vertical depth (TVD)) total depth on Mar. 21.

The primary D5 sand target was penetrated within 50 ft of the predicted depth at 8,225 ft MD (7,330 ft TVD) and Log While Drilling (LWD) Triple Combo (Gamma Ray, Resistivity and Neutron Density) tools logged a total of 39 ft MD (36 ft TVD) net gas pay. While the F5 intersected a high quality D5 sand in this northernmost trap, it appears high on structure and has potentially faulted out the lowermost portion of the D5 sand at the F5 location. LWD data is insufficient to determine the extent intersected pay may potentially connect to a lower, thicker D5 reservoir sequence.

In addition to the D5 sand gas pay, the F5 well intersected 16 ft MD (12 ft TVD) net oil pay in the I3 sand and 25 ft MD (20 ft TVD) net oil pay in the J sand reservoirs. The result in these two sands verifies the extent of the I3 and J sand reserves as previously mapped and logged in the SM71 F1 well. The joint venture has elected that the open hole portion of the F5 be temporarily abandoned for use as a future side-track. The acquired data will determine whether to side-track within the F5 fault block slightly down-dip and away from the fault at the current location in the D5 reservoir to encounter the full D5 reservoir section that may be missing in this location, or to step-out into the main producing fault block and commission an acceleration well in the I3, J, and D5 reservoir.

The joint venture has considered the uncertainty of continuing current operations due to the COVID-19 pandemic. In particular, a planned crew change would be required if the rig was to continue operations introducing heightened risk of operational interruptions during a critical phase. Otto, through its wholly owned subsidiary Otto Energy LLC, holds a 50% working interest and a 40.625% net revenue interest in SM71. Byron Energy Ltd. is operator and holds the remaining interest.