Marginal field refers to a mature oil and gas field which due to various factors (geologic, geographic, technological or economic) may not produce enough net income to make it worth developing at a given time. However; should technical or economic conditions change, such a field may become commercially viable. It is usually associated with small pockets of stranded or bypassed hydrocarbons that have a plateau of a few years. Exploitation of these small yet significant fields is affected by a host of factors including environmental concerns, political instability, access, remoteness, complexity of structures (topside loads, soil condition, water depth etc.) and, of course, the price and price stability of the oil and gas produced in addition to other contractual issues such as agreements between the licensees.

Because of its relative certainty in terms of production history, reservoir history and available assets and infrastructure, it has proven to be attractive to small independents and investors in Nigeria. In terms of location, majority of these fields are located on land or close to the coast in the swamp while others are far away from existing infrastructures, located at great water depths or contain insufficient reserves distributed in multiple pays to consider development on a stand-alone basis. Marginal field development requires concerted efforts involving complex combination, understanding and integration of multiple technical disciplines, human resources and advanced technologies for improving scale of economies.  Therefore, by integrated cluster development and optimized economic scenario, many of these fields could have their economic limits extended significantly.

This course will illustrate through case histories the approach followed for the integrated development of some landmark marginal fields on land, swamp and offshore terrains, with special emphasis on: grouping of marginal fields with economic fields, cluster development, modularization and standardization of process facilities/wells for optimizing cost, revamping existing jack-ups as mobile processing, CAPEX reduction through hired FPSO and use of hydraulic workover units / snubbing units, self-elevated workover platforms (SEWOP) and advanced re-entry techniques like short radius horizontal wells, multilaterals, dual completions, zones transfers etc.