| Autor: |
Gerhard Thonhauser, Abdolali Esmaeili, Behzad Elahifar, Rudolf Konrad Fruhwirth |
| Rok vydání: |
2012 |
| Předmět: |
|
| Zdroj: |
All Days. |
| DOI: |
10.2118/158160-ms |
| Popis: |
The measurement of actual wellbore shape in real-time can be considered as one of the key components to detect problems such as borehole instability. Abnormal wellbore shape will allow drawing conclusions on the stress field and the impact on other sensors' responses as part of LWD measurements. Accurate wellbore caliper measurements in real-time will also allow to determine cement volume requirements with less measurement time. In order to get a quantitative assessment of measurement accuracy, an experimental evaluation of the performance of ultrasonic measurements to determine wellbore geometry while drilling has been performed. A fully automated test robot has been designed and experiments were performed in different drilling fluids and wellbore geometries. That test robot allows emulating vertical as well as lateral movements of a sensor head in an artificial wellbore filled with different types of fluids. Experiments were performed in relation to the radial position of the ultrasonic caliper tool inside the wellbore including different objects inside the borehole to simulate latches or dog legs. The results were compared and the limitations and arising problems for this type of measurement were identified. The wellbore profiles were measured with different axial and rotational survey speeds. The results allowed the quantification of the errors caused by different wave paths and were compared to the actual borehole geometry. In addition, numerical models were applied for the simulation of the measurements; again the results were compared to the actual ultrasonic measurement. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
