Compact Modular Manifold – Standardization and Modularization for Low Cost in a Low Volume Market

Abstract

With increasing volatility in the oil prices, continued focus on low cost solutions is key to maintain a sustainable subsea industry. The industry has and will continue to have a tremendous amount of focus across many standardization initiatives and Joint Industry Programs. The total number of trees awarded since 1961 is in the range of 7 000 - 8 000 representing an annual average of approximately 140 which in the last 10 years has been closer to 300. Assuming 2/3 are installed by a manifold with an average of 4.5 trees per manifold, gives roughly 45 manifolds worldwide per year in the entire subsea industry. Take into consideration that the manifold is the largest piece of equipment in the subsea production system acting as system integrator and interface, bridging the trees with the flow line, often having to absorb the field specific requirements and you have the ultimate standardization challenge in a low volume environment. An important aspect discussed above is that the manifold is indeed part of a bigger system. There are many ways to approach standardization and, in the article, we argue that the optimal approach is to standardize from materials and upwards in the system hierarchy. The approach taken to standardize the manifold was therefore to start with a broad set of system attributes across the subsea production system rather than focusing on the manifold alone. This allows the standardization to be a wholistic approach aiming to optimize the supplier’s operational production strategies, maximize use of lowest cost production processes as well as developing the right standard products. The modular compact manifold has therefore been developed through extensive use of data analytics due both to the large number of variables and the size of the dataset to find the optimum breakdown of the manifold into modules. The manifold shares components and production process with the subsea tree for valves and branch blocks using standard pressure classes. Standard pipe schedules have been identified to further reduce number of parts required in the portfolio. This has enabled configure to order manifolds with a limited number of pre-defined components that can be held in stock to minimize lead time. The use of compact branch blocks has also the allowed the manifold to significantly reduce footprint and weight further ensuring efficient installation.