Interpretation and Analysis of Crosswell Strain Measurements Acquired Using Single-Use Fiber with Slippage Effect: A Field Case Study in the Anadarko Basin

Summary Crosswell low-frequency distributed acoustic sensing (LF-DAS) is a valuable tool for monitoring strain changes induced by fracture propagation, identifying fracture hits, and providing insights into fracture geometries. Single-use fiber, a cost-effective option for crosswell monitoring, is commonly used, but it is prone to slippage under large strain changes caused by fracture hits, complicating data interpretation. This study addresses the challenge by applying a developed interpretation method to crosswell strain data obtained using single-use fiber in the Anadarko Basin, where slippage effects are significant. Our methodology combines comprehensive field data analysis with the visualization of five-parameter plots to interpret strain data from single-use fiber. By utilizing this five-parameter framework (Song et al. 2024), we effectively identify fracture-hit numbers, locations, and timings, even under severe slippage conditions. In addition, we propose four categories to quantify the uncertainty in interpreting strain data affected by fiber slippage. The field data illustrate the complexity of LF-DAS signals with notable slippage and underscore the need for standardized guidelines in fracture-hit interpretation. Analysis of stages from the toe to the heel of the offset well shows reduced slippage asymmetry and improved data quality in near-heel stages. The five-parameter visualization method successfully interprets single or multifracture hits, revealing correlations between slippage levels, fracture-hit frequency, and well spacing. Most fracture azimuths align with N85°E, with an average fracture propagation speed of 20–40 ft/min and fracture half-lengths ranging from 1,500 ft to 3,000 ft. Maximum strain gradients of 0.03–0.05 με/ft were observed, indicating frictional resistance between the fiber and the wellbore. This study presents the first comprehensive analysis of crosswell strain data from single-use fiber experiencing slippage, providing valuable insights into how slippage impacts data interpretation. The proposed five-parameter interpretation method offers a robust framework for industry-wide application and has the potential to set a standard for fracture-hit interpretation using LF-DAS data in various slippage scenarios.