发明授权
- 专利标题: Determining phase transition pressure of downhole retrograde condensate
- 专利标题(中): 确定井下逆行冷凝水的相变压力
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申请号: US10670615申请日: 2003-09-25
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公开(公告)号: US07075063B2公开(公告)日: 2006-07-11
- 发明人: Chengli Dong , Soraya S. Betancourt , Go Fujisawa , Oliver C. Mullins , James J. Dunlap
- 申请人: Chengli Dong , Soraya S. Betancourt , Go Fujisawa , Oliver C. Mullins , James J. Dunlap
- 申请人地址: US CT Ridgefield
- 专利权人: Schlumberger Technology Corporation
- 当前专利权人: Schlumberger Technology Corporation
- 当前专利权人地址: US CT Ridgefield
- 代理商 John L. Lee; Jody Lynn DeStefanis; William L. Wang
- 主分类号: G01V8/00
- IPC分类号: G01V8/00
摘要:
The invention provides a method for determining phase transition pressure of downhole retrograde condensate. An OBM-contamination value is produced from a time-series of fluorescence values produced by measuring fluorescence emitted from a single-phase flow of OBM-contaminated formation fluid in a downhole cell during a cycle of time. The pressure of fluid in the cell is set at a transition boundary by incrementing drawdown pressure and monitoring the presence or absence of a phase transition. An apparent phase transition pressure value associated with the cycle of time is produced by setting apparent phase transition pressure value equal to cell pressure. This process is repeated for several cycles of time to produce a number of pairs of OBM-contamination value and apparent phase transition pressure value as OBM-contamination decreases over time. The value of phase transition pressure is determined by extrapolating from a representation of apparent phase transition pressure values versus OBM-contamination values.