| 摘要 |
A method of evaluating a fluid from a subterranean formation drawn into a downhole tool involves drawing fluid into an evaluation flowline and drawing fluid into a cleanup flowline. A property of the fluid in the evaluation flowline, such as the optical density, can be measured and from this a stabilisation point D1 of the fluid property is detected; that is, the point where the fluid can be considered to be an acceptable virgin formation fluid, uncontaminated, pure or connate. The same property can be measured on the fluid of the cleanup flowline and from this a combined flowline can be deduced. The properties of the fluid in the flowlines can be used to predict or estimate the future fluid properties. The cleanup flowline reduces the level of contaminants in a sample received by the evaluation flowline (for example, see figure 9). A further method determines for a combined cleanup and evaluation flowline a virgin fluid break through property and uses this to project future evaluation flowline fluid properties and determine contamination levels of the various flowlines. |
