Methodology and Array Technology for Finding and Describing Leaks in a Well

Topics: Well integrity/control
Source: SPE 181497
Fig. 1: Illustration of a leak source and how a seven-sensor linear array would measure the differences in the timing (Δt) or phase shift of the waveforms.

This paper presents a new technology and methods that can detect leak locations in a well and illustrate the flow profile of the leak. A substantial amount of time and effort can be expended in repairing leaks in wells, and these methods can reduce that time. The paper shows results and compares them to those of other techniques for a well that had been shut in as a result of a small leak.

Background

Noise tools have been used to detect the sound of leak flow to provide an estimated description on the basis of the magnitude of the noise and the frequency properties. Typically, these tools consisted of one hydrophone or receiver that was limited to frequency and information recorded. The majority of these tools provided stationary measurements that can reduce the optimum intercept of leak or leaks. Many new calculations have been performed that have improved these results; nonetheless, they can still be hampered by physical properties of sound conveyance through layers of hardware or changes in the structure of the well.

During the last few decades, advancements in passive acoustic devices have included broadening measurements, improving quality, and increasing the observed aspects of the measurements. Meanwhile, minimal advancements have been realized in the oil industry for leak/flow detection or characterization. The oil industry needed a device that could accurately locate and characterize leaks and flow behind pipe to reduce risks and nonproductive time. To improve the multiplicity of the sound measurement originating from fluid and gas movement, an array of hydrophone sensors was researched and tested to develop new relationships and characterization possibilities. The acoustic linear array with distributed hydrophone sensors could be synchronized to obtain information emanating from a flow source and fused together to obtain new insight into leaks and flow characterization. 

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 181497, “Methodology and Array Technology for Finding and Describing Leaks in a Well,” by Freeman Hill, Halliburton; Andy Bond, Caelus Energy Alaska; and Michael Biery, Srinivasan Jagannathan, Darren Walters, and Yinghui Lu, Halliburton, prepared for the 2016 SPE Annual Technical Conference and Exhibition, Dubai, 26–28 September. The paper has not been peer reviewed.
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Methodology and Array Technology for Finding and Describing Leaks in a Well

17 December 2016

Volume: 69 | Issue: 1