Abstract
A nonlinear finite-element (NLFE) method is used to model reservoir compaction and the associated surface subsidence caused by the formation pore collapse occurring in the Ekofisk field. The reservoir rock is modeled using an elastoplastic constitutive equation. Observed data of the subsiding Ekofisk field are used to compare the results obtained from the numerical simulation. A specific scenario of reservoir production is utilized as an input to the NLFE code. The predicted subsidence values are found to be in satisfactory agreement with the observed field data. Predictions are made for the compaction of the reservoir and the resulting subsidence in the Ekofisk field for the given production scenario for the next two decades.
| Original language | English |
|---|---|
| Pages (from-to) | 299-310 |
| Number of pages | 12 |
| Journal | Journal of Petroleum Science and Engineering |
| Volume | 10 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1994 |
| Externally published | Yes |
Bibliographical note
Funding Information:The nonlinear finite-element (NLFE) method has been widely used to solve different types of engineering problems. Depending on the nature of the problem, both linear and nonlinear approaches are being adopted. Nonlinear applications treat material and geometric nonlinearities, time-dependent flow and dynamic response, including impact. The elastoplastic constitutive model discussed in the preceding section is implemented in a nonlinear finite-element code, called MICROFEM (Ghamdy, 1986 ). The code is based on another programme, MINIFEM, developed for instructional purposes by Robert L. Taylor (Zienkiewicz, 1977). MICROFEM was developed at the University of Colorado, Boulder, by Prof. Willam and his colleagues. The code borrows its modular architecture, dynamic storage allocation scheme, and the skyline solver from MINIFEM. MICROFEM has been used previously in several research-oriented applications (e.g., Ghamdy, 1986; Azeemuddin, 1988). The code has three important features which make it ideal for its usage in a research environment. These features are expendability, careful accounting of storage use, and portability. The code works on a displacement formulation concept. Various types of elements are supported by the built-in element library. Plane strain, plane stress, and axisymmetric idealization can be easily handled by this code. Two types of convergence norms are available in the code, namely, the load and displacement norms. The input data such as the load/displacement increment, can be provided interactively.
ASJC Scopus subject areas
- Fuel Technology
- Geotechnical Engineering and Engineering Geology