A parametric study of hydraulic fracturing interference between fracture clusters and stages based on numerical modeling

Abstract

Shale oil reservoirs are usually developed by horizontal wells completed with multi-stage hydraulic fractures. The fracture interference between clusters in a single stage and between consecutive stages has an impact on the stimulation quality in terms of fracture geometries and fracture widths. This study introduces a non-planar hydraulic fracture model based on the extended finite element method and its use in quantifying the effects of relevant parameters on multi-stage fracture quality in a realistic shale oil scenario. The numerical model is validated with field diagnostics based on vertical seismic profiling. Relevant parameters including stress contrast, fracturing fluid viscosity, cluster density, and fracturing in consecutive stages are quantitatively analyzed in the numerical study. Results show that effects of stress contrast on fracture quality are greater than those of fracturing fluid viscosity, while the effects are more significant in outer fractures instead of the inner fracture. Denser cluster design leads to greater inhibition for the growth of inner fractures which eventually divert them transversely. In fracturing for consecutive stages, the opening of fractures in the subsequent stages is inhibited and the fracture geometries are also altered by the inter-stage interference caused by the previous stage. Based on field data and numerical modeling, this study identifies key parameters and quantifies their effects on inter-fracture and inter-stage interference in multi-stage hydraulic fracturing in horizontal wells.

Effects of parent well spacing on the poroelastic behaviors in the infill zone in shale oil reservoirs: A case study in Jimsar Shale Oil, China

“…For the infill zone, the 200 m well spacing results in very insignificant reorientations, while the 300 and 400 m well spacing scenarios lead to certain reorientations. Therefore, for the 300 and 400 m well spacing scenarios, a future infill well fracturing job can experience greater frictional loss within the fractures during pumping, as the likelihood of non‐planar fracture growths is higher in these cases with more reorientations in the principal stress field 34,35 . Combined with the observation in Figures 8‐10, it is estimated that, although the pore pressure is largely depleted in the infill zone, the 200 m spacing can reduce the energy required to establish infill well fracture networks.…”

“…Log interpretations and rock mechanical tests are used to determine these mechanical properties, where typical logs such as acoustic logs, resistivity logs, and GR logs are used in the interpretation, and tri-axial tests are used for elastic property evaluation. 34,35 The permeability of the matrix is 0.047 mD with a porosity of 8. pressure values at hydraulic fractures are all equal to the depletion pressure of 25 MPa. After 12 months, pressure depletion is mainly contained in SRVs and the infill zone only has slight pressure decreases.…”

A Modeling Study of the Productivity of Horizontal Wells in Hydrocarbon-Bearing Reservoirs: Effects of Fracturing Interference

“…Based on the detailed fracture length results, it is noted that when the cluster number exceeds two in each stage, the inner fractures are always shorter than the outer fractures. This indicates that the stress interference in simultaneously growing clusters inhibits the growth of the inner fractures and makes the outer fracture more competitive in terms of fracture propagation [38]. The 2-cluster scenario results in a more evenly distributed fracture length.…”

Research progress of CO2 oxidative dehydrogenation of propane to propylene over Cr-free metal catalysts

“…Indeed, the DHP technology was greatly promoted in recent years, which is benefited from a blowout of propane yield due to the success of the shale gas revolution in the USA [15][16][17]. In 2019, shale gas production reached 6321.2 billion cubic meters, accounting for 30% of the total natural gas production in the USA, and the compound annual growth rate of shale gas in the past ten years reached 16.5% (Fig.…”