Abstract
Reserves are getting smaller and harder to find. When they are found, it is ever more important to recover the maximum amount. One place to identify additional reserves is in the grey areas between drilling and geoscience. It is often in the improved interaction between these teams that the best untapped potential exists. On the face of it, there are a number of significant technical hurdles. For example, between the Geophysical and Petrophysical world there is a great gulf in resolution, depths of investigation, and investigated volumes. Petrophysicists investigate centimetres from the wellbore but Geophysicists investigate cubic kilometres. Commonly there are several orders of magnitude difference between the professions but combining them in real time in a 3D environment can yield insights that might have been missed using old technologies. Between Drilling and Geoscience, the gulf is even wider. The two disciplines hardly ever interact directly during the planning and drilling process and in only rare cases are they connected digitally.
Today, there is a sharper focus on financial performance using measures such as NPV, Lifting Costs and Reserves Replacement. As a result, many companies are adopting an "Asset Team" approach to the development of new reserves. Different disciplines within the asset team may be located in a single office, or increasingly in different locations, or even countries. In such situations, it is critical that timelines and objectives are agreed upon. Information must be shared to better plan and drill wells effectively. There are however, a number of obstacles standing in the way of cross-disciplinary sharing of data. Chief among these obstacles are hardware and software impediments. There is a need (or requirement) among users to see data displayed in familiar ways and analysed by familiar tools on common platforms. As such, there needs to be a common environment in which the data can be visualised and discussed by different disciplines.
Real-time information can also aid in other areas such as improving operational efficiency. This information can include the provision of such drilling data as real-time equivalent circulating density (ECD) from pressure-whiledrilling tools, critical when drilling extended reach wells. In addition provision of real-time data to central locations can allow key experts to cover more than one on-going operation, and also minimise potentially hazardous travel to and from remote locations.
This paper will describe new and improved workflow processes that are designed to improve this process, as well as the key software and hardware components of this process. Examples of how these processes and tools have been utilised will be described.
More high risk wells are being drilled where the targets are identified using seismic events. More accurate time to depth correlation is necessary in order to accurately place the well in the target and to select casing points with safety. Accurate casing point selection is crucial to the ability to exploit the reservoir. With an increasing number of fields being developed by extended reach, and/or horizontal wells it is critical that accurate correlation is maintained throughout the well in order to ensure that an achievable well plan is maintained and that well is landed in the target formations. This is especially critical in areas where the seismic definition may be poor. Once in the reservoir interval, operators are literally ‘steering’ the well within the seismic volume, in both the time and depth domains. While accurate time-depth conversion is requisite for these operations, poor agreement between traditional wireline technologies and surface seismic has sometimes increased uncertainty rather than reduced it.
