Refracturing on Horizontal Wells in the Eagle Ford Shale in South Texas - One Operator’s Perspective

2015 ◽  
Author(s):  
Mamadou Diakhate ◽  
Ayman Gazawi ◽  
Robert David Barree ◽  
Manuel Cossio ◽  
Beau Tinnin ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
South Texas ◽  
Eagle Ford Shale ◽  
Eagle Ford

Regional assessment of the Eagle Ford Group of South Texas, USA: Insights from lithology, pore volume, water saturation, organic richness, and productivity correlations

2016 ◽  
Vol 4 (1) ◽  
pp. SC125-SC150 ◽  
Author(s):  
Ursula Hammes ◽  
Ray Eastwood ◽  
Guin McDaid ◽  
Emilian Vankov ◽  
S. Amin Gherabati ◽  
...  
Keyword(s):  
Organic Matter ◽  
Pore Volume ◽  
Water Saturation ◽  
Production Quality ◽  
South Texas ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
The North ◽  
The Impact ◽  
Sweet Spots

A comprehensive regional investigation of the Eagle Ford Shale linking productivity to porosity-thickness (PHIH), lithology ([Formula: see text]), pore volume (PHIT), organic matter (TOC), and water-saturation ([Formula: see text]) variations has not been presented to date. Therefore, isopach maps across the Eagle Ford Shale play west of the San Marcos Arch were constructed using thickness and log-calculated attributes such as TOC, [Formula: see text], [Formula: see text], and porosity to identify sweet spots and spatial distribution of these geologic characteristics that influence productivity in shale plays. The Upper Cretaceous Eagle Ford Shale in South Texas is an organic-rich, calcareous mudrock deposited during a second-order transgression of global sea level on a carbonate-dominated shelf updip from the older Sligo and Edwards (Stuart City) reef margins. Lithology and organic-matter deposition were controlled by fluvial input from the Woodbine delta in the northeast, upwelling along the Cretaceous shelf edge, and volcanic and clastic input from distant Laramide events to the north and west. Local oxygen minimum events along the South Texas margin contributed to the preservation of this organic-rich source rock related to the Cenomanian/Turonian global organic anoxic event (OAE2). Paleogeographic and deep-seated tectonic elements controlled the variations of lithology, amount and distribution of organic matter, and facies that have a profound impact on production quality. Petrophysical modeling was conducted to calculate total organic carbon, water saturation, lithology, and porosity of the Eagle Ford Group. Thickness maps, as well as PHIH maps, show multiple sweet spots across the study area. Components of the database were used as variables in kriging, and multivariate statistical analyses evaluated the impact of these variables on productivity. For example, TOC and clay volume ([Formula: see text]) show an inverse relationship that is related to production. Mapping petrophysical parameters across a play serves as a tool to predict geologic drivers of productivity across the Eagle Ford taking the geologic heterogeneity into account.

Investigation of Production-Induced Stress Changes for Infill-Well Stimulation in Eagle Ford Shale

SPE Journal ◽  
2018 ◽  
Vol 23 (04) ◽  
pp. 1372-1388 ◽  
Author(s):  
Xuyang Guo ◽  
Kan Wu ◽  
John Killough
Keyword(s):  
Horizontal Wells ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Fracture Geometry ◽  
Complex Fracture ◽  
Study Results ◽  
Stress Changes ◽  
Sensitivity Studies ◽  
Stress States ◽  
The Impact

Summary Heterogeneous stress has a great effect on fracture propagation and perforation-cluster efficiency of infill wells. Principal-stress reorientation induced by depletion of parent wells has been investigated by previous numerical studies assuming uniform biwing fracture geometry along the horizontal wells. However, recent field diagnostics indicate that fractures along the horizontal wells are generally nonuniformly developed. In this study, we investigated the impact of depletion of parent wells with complex fracture geometry on stress states, and analyzed stimulation efficiency of infill wells by using an in-house reservoir geomechanical model for Eagle Ford Shale. The model fully couples multiphase flow and rock deformation in three dimensions based on the finite-element method, incorporating complex fracture geometry and heterogeneity. We used this model to accurately characterize pressure distribution and to update stress states through history matching production data of parent wells in Eagle Ford Shale. Depletion of parent wells with nonuniform fracture geometries, which has not been researched thoroughly in the literature, is incorporated in the study. Results show that magnitude and orientation of principal stresses are greatly altered by depletion, and the alteration is uneven because of nonuniform fracture geometries. Stress reversal monitored at the center of the infill location starts after 1 year of production, and it takes another 8 months to be totally reversed for 90°. We also performed sensitivity studies to examine effects of parameters on changes of magnitude and orientation of stress at the infill location, and found that effects of bottomhole pressure (BHP), differential stress (DS), and fracture geometry of parent wells are all significant, whereas effects of the reservoir elastic property are limited. Effects of production time of parent wells are also noticeable in all sensitivity studies. This work analyzes stress-state change induced by depletion of parent wells in Eagle Ford Shale, and provides critical insights into the optimization for stimulation of infill wells.

COMPARTMENTALIZATION OF THE EAGLE FORD SHALE, SOUTH TEXAS – A NOBLE GAS INVESTIGATION

2018 ◽  
Author(s):  
Guolei Han ◽  
◽  
M. Clara Castro ◽  
Toti Larson ◽  
Jean-Philippe Nicot ◽  
...  
Keyword(s):  
Noble Gas ◽  
South Texas ◽  
Eagle Ford Shale ◽  
Eagle Ford
Sign in / Sign up

Export Citation Format

Share Document