编者注：本文首次发表于《Offshore》杂志 2023 年 9 月/10 月号。 单击此处查看完整问题。

作者：Mark J. Kaiser，路易斯安那州立大学

自 2016 年以来，安全与环境执法局 (BSEE) 收集了美国外大陆架运营商的退役支出数据，以估算租赁的退役责任。迄今为止，BSEE 或文献中尚未报告基于 BSEE 数据的汇总统计数据或信息。

该系列由四部分组成，旨在评估美国墨西哥湾深水区（定义为水深大于 122 m（400 英尺））主要退役阶段的 BSEE 成本估算，并推断单位成本统计数据和成本函数该区域。

在第 1 部分中，我们回顾了墨西哥湾深水生产和退役活动，并表明 2022 年退役市场的价值约为 243 亿美元。井和建筑物是最重要的成本类别，其次是管道。

本系列的后续部分将更详细地研究油井堵塞和废弃、结构拆除以及管道退役成本估算。

深水开发理念

深水开发中使用了许多不同类型的结构。固定平台和顺应塔具有延伸至整个水柱的导管架，Bullwinkle（固定平台）水深可达 1,353 英尺（413 m），Petronius（顺应塔）水深可达 1,754 英尺（535 m），这是两个最深的固定平台世界上有许多平台，而浮动结构则使用有浮力的船体，并使用筋腱和锚索固定在某个位置。

深水开发中使用的浮动平台主要有四大类——浮式生产储卸油船（FPSO）、半潜式平台（半潜式平台）、张力腿平台（TLP）和Spar结构——所有这些都在墨西哥湾使用。每种浮式平台都有不同的类别和尺寸，还有一些混合型浮式平台，例如不在船上储存石油的移动式海上生产装置 (MOPU) 和深吃水浮式平台。

2022年，美国墨西哥湾水深超过122 m（400 ft）的固定平台和两座合规塔架共有45座，浮式结构有47座：18座立柱、14座TLP、9座半潜式平台、3座迷你张力腿平台（ MTLP）、一艘 MOPU 和两艘 FPSO。所有生产建筑物主要是石油生产商，这意味着它们的大部分生产流是液态烃（原油和凝析油），并且除了起辅助作用（即交通枢纽）作用的固定平台外，所有建筑物都在生产。

2022 年美国墨西哥湾已完工的深水井中，一半以上位于海底。在深水中，海底井主要采用浮动结构，并且一些浮动结构根本不允许使用干树井（例如FPSO）。大多数深水固定平台，包括顺应塔，都使用干树井，但随着生产在更深水域的发展，其中许多结构也用作湿井回接的宿主。

生产数据

从1947年到2021年，美国墨西哥湾生产了231亿桶（Bbbl）石油和190万亿立方英尺（Tcf）天然气，即约550亿桶油当量（Bboe）。

天然气产量长期处于下降曲线，2021 年产量降至 0.5 Tcf 以下，上次出现在 1960 年代初的水平，而石油产量仍处于过山车状态。

2010 年深水地平线悲剧之后，由于钻探暂停和允许延误，石油产量下降了几年，然后在 2015 年反弹并达到 7 亿桶 (MMbbl) 的新峰值。2020-21 年，新冠疫情大流行这是对该系统的另一次冲击，由于停产和劳动力问题，产量急剧下降至峰值的一半左右。

深水湾于 1977 年开始生产，到 2021 年，其石油产量占美国墨西哥湾产量的 47%，天然气产量占 16%，即约 10.8 桶石油和 30 Tcf 天然气。

2021年，深水湾生产了358兆桶石油和3850亿立方英尺（Bcf）天然气，占该地区石油产量的94%和天然气产量的77%。过去几年，新冠肺炎相关影响显着，但该地区预计将完全恢复并超过大流行前的水平。

从历史上看，墨西哥湾的深水发现一直是含油的。20 世纪 90 年代曾开发过一些大型气田，但大多数都已开采较早，深水天然气产量在 2003 年达到峰值，约为 1.6 Tcf。如今，大多数深水天然气生产都与油田有关，在现场用于公用设施和工艺操作后，其余部分被输送到陆上。

浅水下降是天然气产量急剧下降的主要原因。未来，如果浅水天然气产量继续下降，天然气产量将主要受深水石油开发和伴生气生产控制。低于历史水平的天然气水平可能会成为新常态，肯定低于 1 Tcf/年，并且可能低于 500 Bcf/年。

目前，美国墨西哥湾生产的大部分石油和天然气均来自深水石油生产。预计这两种趋势将持续下去。

退役趋势

自 1978 年以来，在美国墨西哥湾水深超过 122 m（400 ft）的地区，总共安装了 67 个固定平台，拆除了 22 个，留下了 45 个固定平台的活跃（生产）库存。2022 年。

墨西哥湾已安装了三座符合标准的塔（Lena，1000 英尺；Baldpate，1648 英尺和 Petronius，1754 英尺）。2020年，莉娜号退役。

第一个漂浮结构于 1983 年安装，自那时以来，总共安装了 58 个漂浮物，并拆除了 8 个漂浮物，留下了 50 个活跃的漂浮物。2022 年。最近，Independence Hub semi 于 2019 年拆除，MTLP Morpeth 于 2021 年退役。

从井来看，自1966年以来，深水共开钻井7181口，永久废弃井约3929口，暂时废弃井991口，活跃库存井2271口。2022 年。在这 2,271 口井中，约三分之一目前正在生产（约 2022 年有 767 口生产井）。

2016年至2021年，401-1,000英尺水深共有83口井永久废弃，水深>1,000英尺永久废弃井417口。

市场规模

到 2022 年，美国墨西哥湾深水退役市场估计约为 243 亿美元。

油井废弃几乎占市场的五分之四（189 亿美元），其次是结构拆除作业（31 亿美元），约占市场总规模的 10%。油井和建筑物合计占估计市场的 90% 以上（220 亿美元）。

管道退役几乎占总成本的 10%，而场地清理则占总成本的不到 1%。

大部分弃井成本来自与浮体相关的湿井，只有约 10% 的总成本来自固定平台。就结构退役而言，浮标约占总成本的四分之三。

作者简介： Mark J. Kaiser 是位于路易斯安那州巴吞鲁日的路易斯安那州立大学能源研究中心的教授。

Editor's note: This story first appeared in the September/October 2023 issue of Offshore magazine. Click here to view the full issue.

By Mark J. Kaiser, Louisiana State University

Since 2016, the Bureau of Safety and Environmental Enforcement (BSEE) has collected decommissioning expenditure data from operators on the US Outer Continental Shelf to estimate the decommissioning liability of leases. To date, no summary statistics or information based on BSEE data have been reported by BSEE or in the literature.

The purpose of this four-part series is to evaluate BSEE cost estimates in the deepwater US Gulf of Mexico, defined as water depth greater than 122 m (400 ft), across the main decommissioning stages and to infer unit cost statistics and cost functions in the region.

Here in Part 1, we review Gulf of Mexico deepwater production and decommissioning activity, and show that the decommissioning market is valued at about $24.3 billion c.2022. Wells and structures are the most important cost categories followed by pipelines.

Subsequent parts of this series will examine well plugging and abandonment, structure removal, and pipeline decommissioning cost estimates in greater detail.

Deepwater development concepts

Many different types of structures are utilized in deepwater development. Fixed platforms and compliant towers have jackets that extend throughout the water column, up to 1,353 ft (413 m) water depth for Bullwinkle (fixed platform) and 1,754 ft (535 m) water depth for Petronius (compliant tower), the two deepest fixed platforms in the world, while floating structures use a buoyant hull and are fixed at location using tendons and anchor lines.

There are four major categories of floating platform utilized in deepwater development – floating production storage and offloading vessels (FPSOs), semisubmersibles (semis), tension leg platforms (TLPs), and Spar structures – and all are used in the Gulf of Mexico. There are different classes and sizes for each floater type, and a few hybrids such as mobile offshore production units (MOPUs), which do not store oil onboard, and deep draft floating platforms.

In 2022, there were 45 fixed platforms and two compliant towers in the US Gulf of Mexico in water depth greater than 122 m (400 ft) and 47 floating structures: 18 spars, 14 TLPs, nine semisubmersibles, three mini-tension leg platforms (MTLPs), one MOPU, and two FPSOs. All the producing structures are primarily oil producers, meaning that most of their production stream is liquid hydrocarbons (crude oil and condensate), and all the structures were producing except fixed platforms serving an auxiliary (i.e., transportation hub) role.

More than half of completed deepwater wells in the US Gulf of Mexico c.2022 are subsea. In deepwater, subsea wells predominate on floating structures, and some floaters do not permit dry tree wells at all (e.g., FPSOs). Most deepwater fixed platforms, including compliant towers, use dry tree wells, but as production has developed in deeper water, many of these structures have also served as host for wet well tiebacks.

Production data

From 1947-2021, the US Gulf of Mexico produced 23.1 billion barrels (Bbbl) of oil and 190 trillion cubic feet (Tcf) of gas, or about 55 billion barrels oil equivalent (Bboe).

Natural gas production is long on its decline curve and in 2021 production fell below 0.5 Tcf, levels last seen in the early 1960s, while oil production is still on a roller coaster ride.

After the Deepwater Horizon tragedy in 2010, oil production declined for a few years because of a drilling moratorium and permitting delays, before bouncing back and hitting a new peak of 700 million barrels (MMbbl) in 2015. In 2020-21, the COVID pandemic was another shock to the system, and production fell dramatically to about half its peak value from shut-ins and labor issues.

The deepwater Gulf started producing in 1977 and through 2021 has contributed 47% of the oil and 16% of the natural gas produced in the US Gulf of Mexico – some 10.8 Bbbl of oil and 30 Tcf of gas.

In 2021, the deepwater Gulf produced 358 MMbbl of oil and 385 billion cubic feet (Bcf) of gas, representing 94% of the oil and 77% of the natural gas produced in the region. There were significant COVID-related impacts during the last few years, but the region is expected to fully recover and exceed pre-pandemic levels.

Historically, deepwater finds in the Gulf of Mexico have been oily. There were some large gas fields developed in the 1990s, but most of these played out early and deepwater gas production peaked in 2003 at about 1.6 Tcf. Today, most deepwater gas production is associated with oil fields, and after being used onsite for utilities and process operations, the rest is sent onshore.

Shallow-water decline is primarily responsible for the steep drop in gas production. In the future, if shallow water gas production continues to decline, gas production will be controlled mostly by deepwater oil developments and associated gas production. Lower levels of gas than have been seen historically are likely the new norm, certainly below 1 Tcf/yr, and probably below 500 Bcf/yr.

Deepwater oil production is now responsible for most of the oil produced in the US Gulf of Mexico, along with most of its gas. Both trends are expected to continue.

Decommissioning trends

Since 1978, a total of 67 fixed platforms have been installed and 22 removed in the US Gulf of Mexico in water depths greater than 122 m (400 ft), leaving an active (producing) inventory of 45 fixed platforms c. 2022.

Three compliant towers have been installed in the Gulf of Mexico (Lena, 1000 ft; Baldpate, 1648 ft, and Petronius, 1754 ft). In 2020, Lena was decommissioned.

The first floating structure was installed in 1983, and since that time a total of 58 floaters have been installed and eight floaters removed, leaving 50 active floaters c. 2022. Most recently, the Independence Hub semi was removed in 2019, and the MTLP Morpeth was decommissioned in 2021.

In terms of wells, a total of 7181 wells have been spud in deepwater since 1966, some 3,929 wells have been permanently abandoned and 991 wells have been temporarily abandoned, leaving an active inventory of 2,271 wells c. 2022. Of these 2,271 wells, about one-third are currently producing (767 producing wells c. 2022).

From 2016-2021, a total of 83 wells were permanently abandoned in 401-1,000 ft water depth, and 417 wells were permanently abandoned in >1,000 ft water depth.

Market size

The deepwater US Gulf of Mexico decommissioning market is estimated at about $24.3 billion c.2022.

Well abandonment accounts for almost four-fifths of the market ($18.9 billion) followed by structure removal operations ($3.1 billion) at about 10% total market size. Combined, wells and structures account for over 90% ($22 billion) of the estimated market.

Pipeline decommissioning contributes almost 10% and site clearance <1% of total cost.

The majority of well abandonment costs are for wet wells associated with floaters, and only about 10% of the total cost comes from fixed platforms. In terms of structure decommissioning, floaters comprise about three-fourths of the total cost.

About the author: Mark J. Kaiser is a professor at the Center for Energy Studies with Louisiana State University in Baton Rouge, La.