Evaluation of gas well productivity in low permeability gas reservoirs based on a modified back-pressure test method
| Autor: | Youheng Leng, Zhanjun Wei, Youyou Cheng, Chunqiu Guo, Haidong Shi, Liyong Shi, Hui Wang, Mu-wei Cheng, Peijun Zhang, Hongying Xiang, Lingli Liu |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Hydrology
Engineering Petroleum engineering Back pressure business.industry Process (computing) Energy Engineering and Power Technology Geology Interval (mathematics) Test method Geotechnical Engineering and Engineering Geology Stability (probability) Superposition principle Geochemistry and Petrology Pressure-correction method lcsh:TP690-692.5 Economic Geology business Productivity lcsh:Petroleum refining. Petroleum products |
| Zdroj: | Petroleum Exploration and Development, Vol 41, Iss 4, Pp 500-503 (2014) |
| ISSN: | 1876-3804 |
| Popis: | In view of the long pressure stabilization time of low permeability gas reservoirs, the traditional backpressure test was modified based on the idea of isochronal test in order to evaluate gas well productivity accurately. Firstly, carry out continuous well startup using 3–4 incremental working systems at the same time interval without the bottom-hole flowing pressure reaching stability; then carry out a prolonged test using a reasonable working system which requires both the bottom-hole flowing pressure and the production reaching stability; finally shut in the well to allow the pressure recover to formation pressure. If the isochronal test productivity calculation method is borrowed for the modified backpressure test, the drawdown pressure will be overestimated, and calculated productivity will be underestimated. The “process conversion-flowing pressure correction” was used to convert the test process into an isochronal test process, and the bottom-hole flowing pressure correction equation was deduced based on pressure superposition principle to solve the productivity calculation problem with this method. The example indicates that the modified backpressure test method can not only shorten the test time significantly and avoid frequent well startup and shut-in, but also can ensure the accuracy of productivity calculation. Key words: low permeability gas reservoir, bottom-hole flowing pressure, modified backpressure test, “process conversion-flowing pressure correction”, productivity evaluation |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|