Open Access

ARTICLE

Study on Offset Well Pressure Response Characteristics and Interwell Communication Mechanisms in Dual-Wellbore Experiments

Jia He¹, Ang Luo¹, Jing Li¹, Xin Gong¹, Taixin Liu², Yu Peng^2,*
1 Institute of Geological Exploration and Development, CNPC Chuanqing Drilling Engineering Company, Chengdu, China
2 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, China
* Corresponding Author: Yu Peng. Email:
(This article belongs to the Special Issue: Enhanced Oil and Gas Recovery in Unconventional ReservoirsⅡ)

Energy Engineering https://doi.org/10.32604/ee.2026.085570

Received 13 May 2026; Accepted 15 July 2026; Published online 02 September 2026

Abstract

As shale gas development has entered the platform-based stage with continuously decreasing well spacing, the frequency of interwell communication has increased significantly, becoming a major engineering issue that constrains the safe and efficient development of unconventional oil and gas resources. In engineering practice, offset well pressure response phenomena are commonly monitored; however, their intrinsic relationship with different interwell communication types remains unclear, which limits the application of pressure monitoring data for interpreting interwell communication mechanisms and identifying communication types. To address these issues, dual-wellbore hydraulic fracturing experiments were conducted on a large-scale true triaxial physical simulation platform. Different fracture structure conditions (simple fractures, intersecting fractures, complex microfractures, etc.) were constructed in combination with varying in-situ stress states and injection rates. Offset well pressure responses were recorded synchronously, and the corresponding relationship between offset well pressure response characteristics and interwell fracture connectivity modes was systematically analyzed in conjunction with post-fracturing rock sample sectioning and three-dimensional fracture reconstruction results. The experimental results indicate that different interwell communication types exhibit significantly differentiated offset well pressure response patterns, which can be summarized as typical stepped, single-peak, multi-peak, and linear characteristics. Fracture type, in-situ stress state, and injection rate are the key factors controlling interwell connectivity modes and pressure response morphologies. Based on the experimental results, the correspondence between offset well pressure curve morphologies and interwell communication types was established, enabling rapid identification of interwell communication types from pressure monitoring data.

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Keywords

Dual-wellbore experiment; hydraulic fracturing; true triaxial experiment; fracture propagation; interwell communication type; offset well pressure response

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