Reservoir Prediction and Development Challenges in Turbidite Slope Channels

The paper discusses the challenges facing development of deepwater reservoirs deposited in turbidite slope channels. Consideration of the reservoir facies and stacking patterns shows the pitfalls and also the potential for mitigating the effect of flow barriers and baffles within reservoirs. This can impact many aspects of the development including reservoir modeling, well designs and development concept selection. Large Erosional Turbidite Channels are dominated by 4 major facies; Basal lags (good but generally thin reservoirs), slump and debris flows (poor or non-reservoir), high N:G sandy channels (good reservoir), and sinuous channel levees (thin sands difficult to develop). The development of these components and their stacking pattern can be recognized on seismic but there are significant pitfalls. Considering the detailed geometry of the reservoir facies may be important when assessing how easily wells from a fixed platform versus a subsea development can access the reservoir. Low-Relief Channel Levees comprise both sand and mudfilled axis with sandy levees. The muddy axis, heterogeneities in the levees and vertical stacking of channels give rise to development challenges which may require a compromise between the numbers of wells required to mitigate flow barriers and the risk of utilizing complex multiple completion or multilateral wells to minimize well numbers. The high expense of developments in deep water requires a thorough assessment of the subsurface risks. Understanding the potential pitfalls and having appropriate mitigation plans is critical to a successful economic development.