Technologies Contributing to Increased Recovery

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 19418, "Technology Contribution to Increased Recovery," by H. Kjorholt, SPE, A.H. Jorgenvag, SPE, and S. Strom, SPE, StatoilHydro, originally prepared for the 2008 Offshore Technology Conference, Houston, 5-8 May. The paper has not been peer reviewed. The full-length paper focuses on the past and present strategy of StatoilHydro in developing and implementing improved-oil-recovery (IOR) technologies and lists the technologies that have been key to increased recovery and gives indications regarding the way forward. Introduction Increased reserves from IOR activities in mature fields often turn out to be the cheapest and fastest way for an operator to find and develop new hydrocarbons. Technology development is mandatory to increase reserves through IOR. As an operator, StatoilHydro will not in this setting "sit back" and wait for suppliers to come up with new ideas. They want to define the type of technology required to meet their IOR ambitions and establish partnerships with selected institutes and service providers. When the technology is deemed necessary by the research and development organization, business assets, and management of the company, the basis for starting a structured research-and-development program is in place. The next phase is to select the supplier. It is believed that the suppliers also will benefit from such cooperation because a successful project will result in a dedicated customer. Fig. 1 shows how the ultimate recovery in a number of assets has increased since the projects were sanctioned. The average ultimate recovery for all StatoilHydro-operated oil fields today is approximately 50%. The recovery for developments based on dry wellheads is 10 to 12% higher than the recovery in subsea developments. Even though these numbers are high compared to a worldwide average, the objective is to increase recovery by an additional 1 billion bbl, corresponding to a major-field development. Some important characteristics of IOR volumes in mature fields are the following.Their presence is verified (no exploration in the traditional sense is required).Significant infrastructure is already in place.The knowledge of the reservoir is far better than for new developments.The economic boundary conditions are well known. The challenge is to get the oil out of the ground with acceptable cost. The key is to develop technologies that can enhance drainage efficiency. There are no obvious factors such as reservoir properties or drilling challenges responsible for the gap in recovery between subsea and platform developments; it is solely a consequence of the present economic reality of operating subsea vs. from a fixed installation.