In subsea environments, using large-bore/high-rate well designs is often a key contributor to the economic recovery of hydrocarbon resources. Their use is a necessity for accommodating the huge production capacity of the reservoirs they penetrate, with the major benefit of minimizing the number of wells necessary to develop a subsea field. The enthusiasm for using such well designs, however, must also be tempered by a clear understanding of the considerable well control risk they introduce—that risk being an increased level of difficulty in bringing such a well under control if a blowout were to occur. It is common that multiple relief wells, with their inherent complexities and time investment, would be simultaneously required to bring a big-bore blowout under control. The discussion of this fact is, though, not a common topic in industry literature. Instead, capping stacks have been more the focus. Much recent attention has been trained on ensuring that capping stacks are a viable method for quickly responding to a high-rate subsea blowout. This makes sense in light of the simpler, and publicly more palatable, concept of rapidly installing a capping stack on a blown-out subsea well. Still, a capping stack is only as reliable as the wellhead it must connect to. It is because subsea wellheads have such a high chance of being damaged during a blowout that relief wells will always be relied on as the ultimate backstop for ensuring that a subsea blowout can be brought under control.

This reliance on relief wells, as they are traditionally envisioned, has limitations though when addressing a high-rate subsea blowout. Any subsea relief well will have inherent limitations resulting from the architecture of choke and kill lines (flow restrictions) and that of the crossover piping at the blowout preventer (BOP; erosion concerns). In the world of high-rate subsea blowouts, these limitations can sometimes translate into multiple relief wells being required to inject fluid at the rates necessary to affect a dynamic kill. However, the simultaneous use of multiple subsea relief wells to dynamically kill a single blowout has only been tried once in the industry’s history. As a result, some countries require that stopping a blowout must be possible by drilling only one relief well.

In this paper, we describe methods that can be implemented to transcend traditional relief well limitations via using a relief well injection spool (RWIS), with the ultimate goal of dynamically killing a subsea big-bore blowout using a single relief well. The technique varies with water depth. In both shallow-water (826 ft) and deepwater (8,260 ft) environments, the techniques are presented and analyzed that will allow using a single subsea relief well to perform a dynamic kill using 15 lbm/gal drilling fluid injected at 238 bbl/min. This particularly severe scenario, based on a big-bore gas well development in Western Australia, is chosen so that our results will have applicability to most subsea well control events that might arise in the future.

在海底环境中，使用大口径/高速率井设计通常是经济开采碳氢化合物资源的关键因素。使用它们是适应所渗透储层巨大生产能力的必要条件，其主要好处是可以最大限度地减少开发海底油田所需的油井数量。但是，还必须通过对它们引入的相当多的井控风险的清楚理解来节制使用此类井设计的热情，即如果发生井喷，则将这样的井进行控制的难度将增加。通常，要同时控制大口径井喷，需要同时具有多个复杂的井，其固有的复杂性和时间投入。不过，对这一事实的讨论是，在行业文献中不是一个常见的话题。取而代之的是，封顶堆栈已成为重点。最近已经集中了很多注意力，以确保封盖叠层是一种快速响应海底高井喷的可行方法。鉴于在吹干的海底井上快速安装封盖叠层的简单，公开可口的概念是有道理的。尽管如此，封盖叠层仅与其必须连接的井口一样可靠。这是因为海底井口极有可能在井喷期间被损坏，因此将始终依赖救济井作为确保可以控制海底井喷的最终支持。最近已经集中了很多注意力，以确保封盖叠层是一种快速响应海底高井喷的可行方法。鉴于在吹干的海底井上快速安装封盖叠层的简单，公开可口的概念是有道理的。尽管如此，封盖叠层仅与其必须连接的井口一样可靠。这是因为海底井口极有可能在井喷期间被损坏，因此将始终依赖救济井作为确保可以控制海底井喷的最终支持。最近，人们一直在关注如何确保封盖叠层是快速响应海底高井喷的可行方法。鉴于在吹干的海底井上快速安装封盖叠层的简单，公开可口的概念是有道理的。尽管如此，封盖叠层仅与其必须连接的井口一样可靠。这是因为海底井口极有可能在井喷期间被损坏，因此将始终依赖救济井作为确保可以控制海底井喷的最终支持。

按照传统上的设想，这种对救济井的依赖虽然在解决高速率海底井喷时具有局限性。任何海底溢油井都会受到节流和压井管线（流量限制）以及防喷器处的交叉管道（BOP；腐蚀问题）的架构的固有限制。在海底高井喷的世界中，这些限制有时可能会转化为需要以影响动态压井所需的速率注入流体的多个溢流井。但是，在行业历史上，仅一次尝试同时使用多个海底救济井来动态杀死单个井喷。结果，一些国家要求只能通过钻一口溢流井来停止井喷。

在本文中，我们描述了可以通过使用溢流井注入阀芯（RWIS）来克服传统的溢流井限制的方法，其最终目标是使用单个溢流井动态消灭海底大口径井喷。该技术随水深而变化。在浅水（826英尺）和深水（8,260英尺）环境中，均会介绍和分析这些技术，这些技术将允许使用单个海底溢油井，并以238 bbl / min的速度注入15 lbm / gal钻井液进行动态压井。选择这种特别严重的情况是基于西澳大利亚州的一个大口径气井开发，因此我们的结果将适用于将来可能发生的大多数海底井控制事件。