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Analysis

Scheduled Wells Have Higher Success Rate in 2011

Wed, 01/25/2012 - 16:24

Scheduled exploratory wells have had a higher success rate in achieving commercial hydrocarbon production, according to the January-November 2011 drilling statistics published by the CNH. Over this period, half of the 26 completed wells were producing commercial hydrocarbons to be, while 23% were non-commercial producing wells and the remaining 27% were not producing at all.

If these 26 wells are broken down into scheduled and unscheduled wells, as displayed in the charts on the right, the result is clear: a whopping 70% of the scheduled wells were of the commercial producing kind, while only 38% of the unscheduled wells resulted in commercial production. Similarly, 10% of the scheduled wells – only one well – ended up not producing, while 37% of the unscheduled wells – or six wells – were non-producing. It is also interesting to point out that about 60% more unscheduled than scheduled exploratory wells were drilled, showing that as the year went on, Pemex regularly changed its drilling plan.

These findings have to be nuanced: Pemex has for example a very high overall success rate in the shallow water in the southern marine area, according to Carlos Morales Gil, Director General of Pemex Exploration and Production. He points out that one place where unscheduled wells are drilled is at the onshore Burgos basin in the northeast of the country. Changes in the drilling plan are common in this region because of dicult access to the drilling locations due to the region’s challenging geology. Also, the Burgos basin covers much of the north of Tamaulipas and some parts of Nuevo León and Coahuila, regions which have been violence-ridden in the last few months and years and where security concerns have impacted the drilling plan. “The bottom line is: operating is very dierent from regulating,” Morales Gil says.

Gustavo Hernández García, Subdirector of Planning for Pemex Exploration and Production, downplays the importance of success rates of unscheduled wells and what they say about Pemex: “Every year, we drill more or less the number of wells that we planned to, but there will always be dierences between the number of planned wells and the final number of wells drilled in a year. This is part of any sensible company’s development plan.” Hernández García believes that Pemex’s 2011 drilling activities were relatively successful when compared to the development plan for the year. He says that some exploratory wells were switched from the original plan, particularly oshore, where the NOC did not succeed in contracting the required number of jack-ups to fulfill its drilling schedule.

Drilling success