The Third Dimension: Productivity Effects From Spatial Placement and Well Architecture in Eagle Ford Shale Horizontal Wells

2015 ◽  
Author(s):  
William Holcomb ◽  
Randy F. LaFollette ◽  
Ming Zhong
Keyword(s):  
Statistical Significance ◽  
Well Performance ◽  
Eagle Ford Shale ◽  
Multivariate Statistical ◽  
Eagle Ford ◽  
Hydrocarbon Production ◽  
Small Areas ◽  
The Third ◽  
Performance Drivers ◽  
Third Dimension

Abstract Eagle Ford shale formation exhibits highly variability hydrocarbon production rates and EUR within small areas, indicating a highly heterogeneous reservoir. Attempts to determine performance drivers among geological, production or completion data points have produced inconclusive results. For example, production for one cluster of nearby wells may be strongly correlated with proppant quantity, while the trend is not valid for a group of similar wells a short distance away. A more widely valid set of correlations could improve engineering efficiency and productivity across the play. Multivariate statistical modeling has indicated that wellbore architecture factors influence well performance. Such models have determined relative influence of such factors as fracturing fluid type and volumes, proppant sizes and volumes, etc. On the wellbore architecture side, prior studies found that surface latitude and longitude are among the strongest drivers. However, these studies largely omitted consideration of the third dimension (relative vertical location in the reservoir). This study evaluates productivity influences from azimuth, dip, porpoising, and TVD from heel to toe (vertical zone coverage). It also reconsiders previously studied factors (such as fracturing fluids and proppants) with a considerably larger body of data—especially longer-term production data—than was available for the prior studies. The goal is to determine geological, wellbore architecture, and completion factors that show statistical significance as performance drivers, and where they are applicable if the results vary across the play.

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

2015 ◽  
Author(s):  
Mamadou Diakhate ◽  
Ayman Gazawi ◽  
Bob Barree ◽  
Manuel Cossio ◽  
Beau Tinnin ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Horizontal Wells ◽  
Well Performance ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Fracture Geometry ◽  
Testing Program ◽  
Pilot Testing ◽  
Fracture Gradient ◽  
Lateral Length

Abstract This paper outlines a refrac pilot testing program conducted in the Eagle Ford Shale. As wells in the Eagle Ford accumulate production over time and the pressure around the horizontal wellbore declines, it is important to also consider communication due to offset fracture stimulation. Refracturing trials in older fields, such as the Barnett Shale have yielded a positive enhancement of well performance (Siebrits et al., 2000). This paper evaluates the concept of diverting fluid and proppant along horizontal wells in the Eagle Ford, while considering any communication with older producing wells during refracturing operations. Pumping data acquired during the refracturing is used to explain some of these concepts. Modeling of induced fracture geometry, considering the effect of current pore pressures, is conducted with a fully three-dimensional hydraulic fracture numerical simulator. The pressure of the subject zone may affect the containment and rate of growth of the new fractures, as well as the re-orientation of the existing fractures. Refracturing an old horizontal well with 5,000 ft lateral length and more than 800 existing perforation holes in the casing is very challenging and requires a careful integration of reservoir knowledge, completions skills and experience. The technical team at Pioneer Natural Resources has developed an integrated workflow to design and execute a refracturing job for an Eagle Ford well. The work flow includes: 1) identification of the lower pressure areas along the lateral using surveillance data from the well, such as microseismic, tracer logs, and production data. 2) identifying which wells within the drilling schedule are offsetting older wells that have high cumulative production, and 3) designing a single fracturing job with several sub-stages separated by diverting agents. Each sub-stage is intended to target specific areas along the lateral, which were previously identified as low pressure zones. Volumes and pump schedules will be specific for each candidate and are based on but not limited to proximity to an offset well, lateral length, and existence of geological structures such as faults and fractures in the area. The results from this pilot testing program such as the radioactive tracers and the fracture gradient changes before and after refrac will be evaluated upon completion of the field execution.

scholarly journals Cyclic CH4 Injection for Enhanced Oil Recovery in the Eagle Ford Shale Reservoirs

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3094 ◽  
Author(s):  
Yuan Zhang ◽  
Yuan Di ◽  
Yang Shi ◽  
Jinghong Hu
Keyword(s):  
Capillary Pressure ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Molecular Diffusion ◽  
Well Performance ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Well Production ◽  
Operation Parameters ◽  
Shale Reservoirs

Gas injection is one of the most effective enhanced oil recovery methods for the unconventional reservoirs. Recently, CH4 has been widely used; however, few studies exist to accurately evaluate the cyclic CH4 injection considering molecular diffusion and nanopore effects. Additionally, the effects of operation parameters are still not systematically understood. Therefore, the objective of this work is to build an efficient numerical model to investigate the impacts of molecular diffusion, capillary pressure, and operation parameters. The confined phase behavior was incorporated in the model considering the critical property shifts and capillary pressure. Subsequently, we built a field-scale simulation model of the Eagle Ford shale reservoir. The fluid properties under different pore sizes were evaluated. Finally, a series of studies were conducted to examine the contributions of each key parameter on the well production. Results of sensitivity analysis indicate that the effect of confinement and molecular diffusion significantly influence CH4 injection effectiveness, followed by matrix permeability, injection rate, injection time, and number of cycles. Primary depletion period and soaking time are less noticeable for the well performance in the selected case. Considering the effect of confinement and molecular diffusion leads to the increase in the well performance during the CH4 injection process. This work, for the first time, evaluates the nanopore effects and molecular diffusion on the CH4 injection. It provides an efficient numerical method to predict the well production in the EOR process. Additionally, it presents useful insights into the prediction of cyclic CH4 injection effectiveness and helps operators to optimize the EOR process in the shale reservoirs.

The impact of pressure and fluid property variation on well performance of liquid-rich Eagle Ford shale

2016 ◽  
Vol 33 ◽  
pp. 1056-1068 ◽  
Author(s):  
S. Amin Gherabati ◽  
John Browning ◽  
Frank Male ◽  
Svetlana A. Ikonnikova ◽  
Guinevere McDaid
Keyword(s):  
Well Performance ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Property Variation ◽  
Fluid Property ◽  
The Impact

Stratigraphic Characterization of the Eagle Ford Shale to Identify the Best Landing Zone: A Semi-analytical Workflow

2022 ◽  
pp. 1-62
Author(s):  
Ajit K. Sahoo ◽  
Vikram Vishal ◽  
Mukul Srivastava
Keyword(s):  
Local Level ◽  
Well Performance ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Landing Zone ◽  
Production Behavior ◽  
Key Drivers ◽  
The Relationship

Placement of the horizontal well within the best landing zone is critical to maximize well productivity, thus identification of the best landing zone is important. This paper illustrates an integrated semi-analytical workflow to carry out the stratigraphic characterization of the Eagle Ford shale to identify the best landing zone. The objective of this work is twofold: 1) to establish a workflow for stratigraphic characterization and 2) to understand the local level variability in the well performance.To establish the workflow, we have used the production data, petrophysical information and regional reservoir property maps. As a first step of the workflow, we subdivided the Eagle Ford shale into nine smaller stratigraphic units using the wireline signatures and outcrop study. In the second step, we have used statistical methods such as linear regression, fuzzy groups and theory of granularity to capture the relationship between the geological parameters and the well performances. In this step, we identified volume of clay (Vclay), hydrocarbon filled porosity (HCFP) and total organic carbon (TOC) as key drivers of the well performance. In the third step, we characterized the nine smaller units and identified four stratigraphic units as good reservoirs with two being the best due to their low Vclay, high HCFP and high TOC content.Finally, we reviewed the well paths of four horizontal wells with respect to the best stratigraphic units. We observed that production behavior of these wells is possibly driven by their lateral placement. The better producing wells are placed within the middle of the best stratigraphic units whereas the poor wells are going out the best stratigraphic units. This investigation provides a case study that demonstrates the importance of integrating datasets to identify best landing zones and the suggested workflow can be applied to other areas and reservoirs to better identify targetable zones.

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