DEVELOPMENT OPTIONS FOR OFFSHORE OIL AND GAS FIELDS: IMPLICATIONS FOR OPTIMUM LONG-TERM RECOVERY

Technology used in the Australian offshore oil and gas industry in recent years has diversified with the introduction of innovative concepts for field developments. These innovations are aimed at cost reduction and greater access to reserves, especially those in small and remote fields. Further innovations are anticipated as research progresses in several areas of potential cost reduction. Changes in technology can dramatically affect the relative economics of data acquisition, contingency planning and the extent of field development. Drilling and workover economics, well servicing, reservoir surveillance and the opportunities for infrastructure development are strongly dependent on the choice of development technology. These choices, in turn, have implications for long-term recovery, including the discovery and development of new pools and extensions to known pools, overall field recovery factors, the opportunities for development of gas caps and nearby fields, and the future potential for enhanced oil recovery (EOR).Government involvement in development approvals in various countries has diverse objectives. The Australian Petroleum (Submerged Lands) Act specifies as one objective the optimum long-term recovery of petroleum. Critical areas of interest are pre-development planning with necessarily incomplete information, the phenomenon of unexpected reserves growth, and provision for contingencies such as well failures. Early drilling and completion decisions and infrastructure planning have major effects on future developments. Subjects of direct relevance for future improvements in development economics include reductions in pipeline construction costs, reductions in the cost of drilling from mobile rigs and flexibility in completion design.