West Delta Block 84-Methodology and Analysis of a Previously Orphaned Field

Abstract This paper describes the effort to justify, document and confirm proven, unproven, undeveloped and bypassed remaining oil and gas reserves in West Delta Block 84 Field, at one time an orphaned field off the coast of Louisiana. The methodology used for the evaluation provides an insight of how to identify, quickly and efficiently, worthwhile and economic marginal properties, even with incomplete or missing information. This methodology is being used as a part of the development of an expert system for the evaluation of marginal and/or orphaned wells, reservoirs and fields. West Delta Block 84 is located off the coast of Plaquemines Parish, Louisiana, near the mouth of the Mississippi River in about 20 feet of water. Conoco discovered it in 1955 with the drilling of the SL 2551 No. 1 well to a total depth of 14,500 feet. It has produced over 9.8 million barrels (MMSTB) of oil and 21 billion cubic feet (BCF) of gas. It was shut in for a period of almost ten years while languishing in and out of bankruptcy court from 1990 to 2000 and was actually orphaned by the state at one point during this time. Available data was organized and pieced together for the field, but was still lacking in completeness. As in most cases when dealing with older marginal fields, an ability to deal with missing and incomplete information was necessary to complete the analysis. Introduction There are reportedly 343,030 inactive, shut-in and/or orphaned wells nationwide, of which 34,355 are in Louisiana. In many cases, these wells are idle and orphaned, not because their resources have been depleted, but because of other factors. These factors might include low product price, high cost of operations, unrelated financial problems or the inability or lack of resources to properly describe the reservoir and identify the potential for additional recovery, among other things. It is, simply, not known, with any accuracy, to an outside party looking in, exactly why a well is shut-in or orphaned. Historically, small and large independent producers have entered into fields previously operated and owned by the major oil companies. These under-financed and understaffed independents find themselves working off cash flow and unable to find the financial resources to work-over the idle wells, much less do the research that many of the wells and reservoirs deserve and need. The wells may have potential, but no one has the time or the money to pursue these most likely marginal targets. There is an incentive to identify potential in these shutin/ orphaned wells since their plugging would be terminal and, in the case of orphaned wells, would cost taxpayers money. In the period of four years, from 1996 to 2000, there were reportedly 712 wells plugged in Louisiana for $14,090,000, which gives an average cost of $17,890 per well. Presently, there is a new powerful incentive for not plugging wells that might be returned to production as the processing price of oil has reached $56/bbl with no signs of leveling-or dropping in the future.