Peter Howard Wertheim
OGJ correspondent
RIO DE JANEIRO, Nov. 14-- Brazil's state-owned Petroleo Brasileiro SA (Petrobras) has begun drilling an oil well in Serra field in the northern state of Rio Grande do Norte that will have the largest ratio between vertical depth and horizontal reach of any well in Brazil.
Petrobras 7-SER-17D will have a vertical depth of 950 m, a horizontal distance from the well of 2,800 m, and a total measured depth of 3,300 m. Queiroz Galvão's QG-2 rig is drilling the well, which is expected to be completed in December.
The Serra campaign is being conducted carefully due to the environmental sensitivity of the region, say Petrobras officials. The well is being drilled from an onshore location to a target below 3 m of water.
Engineer Vicente Abel Soares Costa said Petrobras's Rio Grande do Norte business unit is conducting an environmental program in Serra to ensure that drilling will not hurt the environment. Among the safeguards are the use of biodegradable fluids, gravel drying, the extraction and containment of generated liquid and solid wastes, and sanitary facilities at drilling locations.
Serra field has 16 producing wells, of which 12 are long-reach types. The average production of each well is 100 cu m/day of 30º gravity oil.
