Redevelopment of the Brighton Marine Field, Trinidad . . . the early days

Abstract

In October 1999, the Brighton Marine Block was awarded to Venture Production Company Trinidad Limited and Petrotrin, the Trinidadian National Oil Company, with Venture as operator.The challenges to improved field recovery posed by such a complex field, with more than 50 years of production history, are many. The field has potential, but requires new interpretations and ideas based on both new and old datasets, a phased programme of rehabilitation and a long-term development plan that will generate immediate value without compromising long-term oil production.Discovered in 1951, the Brighton Marine Field has produced almost 58 10 6 STB from an oil in place of over 500 10 6 STB. Production peaked at 14 000 BOPD in 1967 but had not exceeded 1000 BOPD since 1983.Some 275, mostly deviated, wells were drilled into the field from 11 onshore pads and 9 offshore platforms. In the year since Venture assumed operations, production rose to nearly 2000 BOPD through field infrastructure rehabilitation, well workovers and the implementation of new field management processes. In early 2001, the first new well proved the presence of a commercial quantity of petroleum in a hitherto undepleted part of the field.It is very early in the rehabilitation process and much remains uncertain, but significant progress has been made in understanding the field and tapping its full potential. The field's first 3D seismic survey, acquired in 1997, has provided a significant enhancement to the understanding of a structurally and stratigraphically complex field. The field compartmentalization and 50 years of production, have complicated the distribution of pressures, sweep and compaction. In order to mitigate risks, a phased strategy was implemented. This process focuses initially on the most straightforward, cost-effective opportunities. These redevelopments are designed to maximize data collection, test new models and help finance more extensive developments. Already, this approach is starting to yield results, although it is still early days.

Stress state and its influence on drilling performance in the Brighton Marine field, Trinidad

“…Wallis et al (2002) documented a typical stratigraphic section. This shale-dominated succession consists of Upper Miocene sediments of mixed lithology overlying the Lower Miocene Nariva formation unconformably overlying Cretaceous basement.…”

“…However, this cannot be confirmed or otherwise as the mechanical behaviour was not quantified. Wallis et al (2002) noted that the field is a large four-way dip closure and that the recent 3D seismic data appear to exhibit a strike-slip fault in the northern part of the survey which may be the Central Range (Warm Springs) fault or a splay from it. Wallis et al commented that the 3D seismic data suggest that strike-slip faulting played a significant part in the development of the field which, combined with observations of compressive faulting, implies oblique compression resulting in the inversion of Cretaceous faults.…”