Offshore Quartering Study - A Five Year Projection Into An Expanding Gulf Of Mexico Operations
Authors: Franzen Donald M. , Hyde Leonard B. 
Published: October 2008

The South Texas Offshore District of ARCO Oil & Gas Company anticipates a substantial increase in offshore production platforms over the next few years. Associated with this is a proportionate increase in the need for production personnel to operate these platforms. The purpose of this study was to evaluate several options for quartering and transporting these personnel. The two options considered in this study were:Quarter personnel on every production platform or special quartering platformsTransport personnel daily from land shore bases

Although the South Texas District encompasses all of offshore Texas and a significant portion of offshore Louisiana, the study was limited to offshore Texas and the West Cameron area offshore from Louisiana. This was done because most of the future activity seems concentrated there. The results from this study indicate that the offshore quartering mode of operation was generally lower in cost. Specifically, the high incremental transportation cost for shore base versus offshore operation justifies significant capital outlays for offshore quartering facilities.

Introduction

This study considered two basic time frames. The first looked at all platforms that were scheduled for start-up by the end of 1981 in the offshore Texas area. The second looked at those on line by the end of 1985. Offshore Texas was divided into a Corpus Christi area and a Sabine Pass area (See Figures 1 and 2). For the 1981 case, the Corpus Christi area was not evaluated since no platforms are scheduled for start-up by then. The approaches for the 1981 and 1985 cases were different. In the 1981 case, most major variables were known. The platforms being considered in the 1981 case are listed in Appendix A. For the 1985 case, there are potential discoveries that could result in additional platforms by 1985. As a result, the number of platforms forecasted is a function of the economic discovery chance factor for unexplored leases. The approach taken in this study is as follows:The minimum time between discovery and startup is 4 yrs. (See Appendix A).The only leases considered as potential discoveries for the 1985 study were those to be drilled in 1980.Discovery change factors of 50, 30, and 20 percent were applied to each of these leases to determine the number of new platforms not already planned. (See Appendix B).The new platforms above were added to the already planned platforms to get total platforms for 1985

Discussion

The geographic distribution of platforms within the Sabine Pass and Corpus Christi areas logically led to a further division into four groups; Sabine Pass Deep, Sabine Pass Shallow, North Corpus Christi, and South Corpus Christi areas. For example, the Sabine Pass Shallow area covers an arc up to 65 miles offshore and the Sabine Pass Deep area is anything beyond. (Figures 1 and 2). The primary tool used for evaluating this project was an economic evaluation computer program, PLATFAC, which was developed within ARCO's Staff Planning and Evaluation Group.