Abstract

Minimizing well costs and associated risks requires well construction planning techniques that account for the interdependencies involved in the well design. The inherent difficulty is that most design processes and systems exist as independent tools used for individual tasks by the various disciplines involved in the planning process. In an environment in which increasingly difficult wells of higher value are being drilled with fewer resources, there is now, more than ever, a need for a rapid well-planning, cost- and risk-assessment tool.

This paper presents an automated process for integrating the well construction planning workflow and accounting for process interdependencies. The process is based on a prototype drilling simulator developed with a consortium of major oil companies in 1999–2000 that first demonstrated the technical feasibility of such a tool. The highly interactive process is encompassed in a software system that

  • allows well construction practices to be tightly linked to geological and geomechanical models

  • enables asset teams to plan realistic well trajectories by automatically generating cost estimates with a risk assessment, thereby allowing quick screening and economic evaluation of prospects

  • enables asset teams to quantify the value of additional information by providing insight into the business impact of project uncertainties

  • reduces the time required for drilling engineers to assess risks and create probabilistic time and cost estimates faithful to an engineered well design

  • permits drilling engineers to immediately assess the business impact and associated risks of applying new technologies, new procedures, or different approaches to a well design.

Discussion of these points and field examples illustrate the application of the workflow and verify the value, speed, and accuracy of this integrated well planning and decision-support tool.

Introduction

In 2000 Schlumberger Cambridge Research completed development of a prototype software drilling simulator.1 This prototype, shown in Figs. 1, 2, and 3, was developed as part of an agreement with the MoBPTeCh consortium (a technology consortium of Mobil, BP, Texaco, and Chevron). The aim of the prototype was to offer a "proof of concept" that a simulator could address the needs of difficult well planning issues. The project demonstrated the value and viability of a tool that would provide an integrated and more automated approach to well planning.

The prototype simulator was an evolution of a real-time wellbore stability concept, and it was used as a test-bed for the development of ideas that will be embodied commercially within the software system discussed in this paper.

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