Methodology to Improve Well Test Interpretation and Reservoir Characterization in a Fluvial Reservoir Environment.
Abang Ahmad, Khairunnisa, Mazuki, A and Mohd Shuib S.
Engineering Honours Degree, 2010
University of Adelaide
The relevance of this project is to develop a new integrated methodology to improve well test interpretation and reservoir characterization in fluvial environment since there is no recent reservoir-analytical model that may accurately describes the general behaviour of a well producing from channel sand in a fluvial environment. The proposed methodology has incorporate integration of analytical and numerical models, combined with 3D geological modelling with core analysis, production data and geological information to improve interpretations in braided fluvial environment.
A braided fluvial environment forms an extremely heterogeneous reservoir which usually shows negative skin and high permeability despite the absence of any natural or induced fractures that has been referred as the geochoke phenomenon. Hence, an extensive literature review is conducted to understand geochoke phenomenon that is further investigated through reproduction of the phenomenon using data obtain from published case studies. A comprehensive and correct reservoir characterisation is crucial to ensure a high quality of reservoir modelling in reservoir simulation. The dependency of this model will leads to future decisions on developing the field.
In this project, a software known as Saphir is heavily used in generating analytical models and numerical models. The software runs under the principle of Pressure Transient Analysis that incorporated pressure and flow rates as inputs. Since analytical model is highly idealized in characterising heterogeneous reservoir, numerical model is incorporated to improve interpretation in well testing. After the generation of analytical and numerical models, a comparison analysis on the outcomes from both models is establish to investigate any change in the key parameters such as skin and permeability. The differences in the outcomes are acknowledge and incorporated in the development of a new methodology to improve fluvial environment characterisation.
Analysis on the findings of fluvial characterization especially in the area of geochoke phenomenon is summarized at the end of the report. In addition, integration of data, people, time, and process are also addressed in the report together with the role of well testing interpretation involving analytical and numerical model. Finally, some recommendations are made to improve the new develop methodology.