| 摘要 |
Methods and systems for determining a standoff between a downhole tool and a geological formation are provided. The standoff may be determined using a standoff measurement system that includes an electrode component, one or more electronics components, one or more transformers, and one or more processor units. When the standoff is expected to be no more than a first distance, a first measurement can be made where both originating and resulting electrical signals are induced at the electrode component. When the standoff is expected to be no less than a second distance, a second measurement can be made where an originating electrical signal is induced at one of the transformers while a resulting electrical signal is induced at the electrode component. |
| 主权项 |
1. A method for determining a standoff between a surface of a downhole tool and a surface of a geological formation, the method comprising:
providing the downhole tool that includes an electrode component exposed from a surface of the downhole tool, one or more transformers exposed from the surface of the downhole tool, and one or more electronics components; when the standoff between the surface of the geological formation and the surface of the downhole tool is expected to be no more than a first distance:
imposing, using at least one of the electronics components, a first originating electrical signal at the electrode component,measuring, using at least one of the electronics components, a first resulting electrical signal at the electrode component to obtain a first measurement, the first resulting electrical signal generated as a result of the first originating electrical signal, andfitting, using one or more processor units, the first measurement to a first modeled tool response to determine a first standoff between the surface of the downhole tool and the surface of the geological formation; and/or when the standoff between the surface of the geological formation and the surface of the downhole tool is expected to be no less than a second distance:
imposing, using at least one of the electronics components, a second originating electrical signal at a first transformer,measuring, using at least one of the electronics components, a second resulting electrical signal at the electrode component to obtain a second measurement, the second resulting electrical signal generated as a result of the second originating electrical signal, andfitting, using one or more processor units, the second measurement to a second modeled tool response to determine a second standoff between the surface of the downhole tool and the surface of the geological formation. |
