Well Cement Position Estimation Using Pressure-Corrected Borehole Diameter
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Solution Overview
Problem
Current methods for determining the position of the top of cement (TOC) in a terranean borehole are inefficient and inaccurate, often requiring time-consuming and costly processes, such as sonic tools, which can lead to incomplete cementation and potential leakage between the casing and the formation.
Innovation Solution
A method involving the comparison of pressure measurements at different times during the cementing process, combined with volume monitoring and rheology models, to estimate the position of fluids and correct the average diameter of the borehole, allowing for precise placement of cement slurry through perforations or the annulus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sonic tools are used to determine TOC position, then measurement accuracy is improved, but operational time and cost increase
Solution Approach 1:
The patent replaces mechanical/sonic measurement tools with a pressure-based monitoring system. By measuring pressure changes in the annulus during cementing operations and comparing them to predicted pressure profiles, the system determines TOC position without requiring sonic tools, thereby reducing operational time while maintaining measurement accuracy.
Solution Approach 2:
The system uses the existing cementing operation's own pressure data to determine TOC position. The pressure measurements taken during the normal cementing process are utilized to assess cement placement accuracy, eliminating the need for separate measurement operations and reducing overall operational time.
2Measurement precision
If sonic tools are used to determine TOC position, then measurement accuracy is improved, but operational cost increases
Solution Approach 1:
The patent replaces expensive sonic measurement tools with a pressure monitoring system that utilizes data already collected during the cementing operation. This substitution eliminates the need for additional expensive equipment while maintaining the ability to accurately determine TOC position.
Solution Approach 2:
The system uses pressure as an intermediary parameter to infer TOC position. Instead of directly measuring cement position with expensive tools, the system measures pressure changes that occur during cementing and uses these changes to calculate TOC position, providing a cost-effective measurement approach.
3Productivity
If pressure monitoring is used to estimate fluid position, then operational efficiency is improved, but measurement precision may be compromised
Solution Approach 1:
The system continuously monitors pressure during the cementing operation and compares actual pressure readings against predicted pressure profiles. This feedback mechanism allows for real-time assessment of cement placement and enables corrective actions if the TOC position deviates from the target, maintaining measurement precision while improving operational efficiency.
Solution Approach 2:
The system uses preliminary pressure data collected during the cementing operation to estimate TOC position before the operation is complete. This allows for early detection of placement issues and enables corrective actions to be taken while the cement is still being pumped, improving both efficiency and accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides a more accurate and efficient estimation of the cement position, reducing the need for secondary confirmation processes and enabling immediate corrective actions, thus ensuring effective cementation and reducing operational costs and time.
Implementation Method 1
comparing a pressure of the collection fluids measured at an inlet of a passage of the tubular string at a first time with a pressure of the collection of fluids measured at the inlet of the passage of the tubular string at a second time
Implementation Method 2
estimating a position of the collection of fluids in the borehole based on the comparison of the pressures of the collection of fluids measured at the first and second times
Data Source
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AI summary
A method for cementing a borehole includes pumping a collection of fluids into the borehole through a tubular string in the borehole, flowing the collection of fluids up an annulus positioned between the tubular string and a sidewall of the borehole, monitoring a volume of the fluids pumped into the borehole, performing a first estimation of a position of the fluids based on the volume of the collection of fluids pumped into the borehole, and an initial estimate of an average diameter of the sidewall of at least a portion of the borehole, calculating a corrected estimate of the average diameter based on the first estimation and a pressure of the fluids measured at an inlet of the tubular string, and performing a second estimation of the position of the fluids based on the volume of the fluids pumped into the borehole and the corrected estimate of the average diameter.