LAUSR

Accurate knowledge of formation fracture pressure is essential to optimize well design at all stages of the field development. However, erroneous prediction of formation fracture pressure can lead to process safety incidents such as surface and underground blowouts. While fracture pressure prediction models have been developed for some sedimentary basins, it is difficult to transfer these models to areas beyond the regions of study. In the Niger Delta basin, few fracture pressure prediction models have been developed. However, these models were developed primarily from leak-off test data acquired from the normally pressured intervals. Basically, the existing Niger Delta fracture pressure prediction models lack the leak-off test measurements in the overpressure intervals, because such data are not available. In this paper, a new fracture pressure prediction model that can be applied to normally pressured intervals and overpressure zones is being proposed. Model development is based on establishing a relationship between fracture pressure, true vertical depth and magnitude of overpressure using several leak-off test data acquired from over 100 wells in various fields scattered across the basin. Unlike the previous models, the newly developed model incorporates leak-off test measurements from the overpressure intervals in the basin. In general, the newly proposed model can be used with a high degree of confidence to predict the fracture pressure required for safe and economic well planning across the entire basin.