Geological reasons causing rapid rate decline. A case study of Field T, Russia

Scientific and Technical Challenges in the Well Drilling Progress

Kuzmin, S.^1,2 ; Rukavishnikov, V.^1 ; Sukovatyi, V.^2

Tomsk Polytechnic University, Tomsk, Russia^1

Gazpromneft-Orenburg, Orenburg, Russia^2

关键词: Analytical and numerical methods;    Attribute analysis;    Drilled wells;    Facies models;    Reservoir characterization;    Reservoir quality;    Structural interpretation;    Well test data;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/24/1/012046/pdf
DOI  :  10.1088/1755-1315/24/1/012046

来源: IOP

【 摘 要 】

The paper introduces the complex approach to determining possible geological reasons causing rate decline in the wells of Field T, Russia. Therefore, possible geological reasons are sequentially considered and were divided into three main groups: 1) rate decline due to poorer reservoir quality; 2) rate decline due to facies lateral substitution; 3) rate decline due to active fault tectonics. The most appropriate facies models were constructed on the basis of all available data. Besides, in this study, core, well logging, seismic and well test data were integrated for the fullest reservoir characterization. The core from several recently drilled wells was described in detail to determine clue features. Further, seismic data were interpreted: structural interpretation, including faults and attribute analysis, was implemented. Appropriate electrofacies models were chosen as well. At the final stage, all previously-mentioned data were integrated with appropriate facies model construction. However, as it turned out later, the facies model was not the key factor affecting the rapid decline that appeared in some wells. It is suggested that very proximal faults can be a possible explanation. To confirm this suggestion, well test data were additionally used and both analytical and numerical methods were applied to show the consistency of this theory.