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CASE STUDY

Pulsed-Neutron Workflow Saved 35 to 45% in Stimulation Cost Per Well

Low-risk, pumped-down pnl for cost-effective completions in lateral wells

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Opportunity

Unconventionals

Opportunity
Specific Challenge

Reduce completion stages in lateral wells

REGION - EAGLE FORD SHALE, TEXAS REGION - EAGLE FORD SHALE, TEXAS

Eagle Ford Shale, Lavaca County, Texas

REGION - EAGLE FORD SHALE, TEXAS

Challenge

  • Reduce completion stages in lateral wells 
  • Solution must be reliable and cost effective 

Solution

  •  Halliburton proposed a low-risk, pumped-down pulsed-neutron log (PNL) for continuous petrophysical and mechanical properties to optimize completions 
  • A geosteering software workflow was also recommended for nearby vertical logs to enhance the calibration method 

Result

  •  Reduced the number of completion stages in wells from 25- to 30-stage geometric completions to 16- to 19-stage optimized completions
  •  Stimulation cost savings ranged from 35 to 45% per well 
  • Better reservoir understanding for well placement 
  • Optimized completions for better cost efficiencies

Overview 

Evidence continues to indicate that the geometric placement of fracture stages and perforation clusters in horizontal wells results in variable well production, with many clusters contributing little or no production. Any engineered completion design should require stages to be segregated by similar petrophysical and mechanical properties. To reduce the cost per barrel of oil equivalent (BOE) and improve estimated ultimate recovery (EUR), Halliburton recommends using a novel log-derived completion method. This helps to improve perforation cluster and stage location selection to optimize fracture placement.

Challenge 

On an Eagle Ford multiwell project, Devon sought to reduce the number of completion stages in its lateral wells. Drilling and completion costs ranged between USD 8 to 12 million per well. Traditional stimulation consisted of 200-ft geometric stages, which had led to an average staging of approximately 25 stages per well. 

Solution

Halliburton proposed a low-risk, pumped-down pulsed-neutron log (PNL) to provide the most cost-effective and reliable solution for deriving continuous petrophysical and mechanical properties in the lateral wells for optimized completions. A workflow using geosteering software to project nearby vertical logs along the lateral wells was added to enhance the calibration method. This enhancement removes the need to regularly add a PNL to select vertical wells. In addition, this method reduces the uncertainty in the PNL calibration and interpretation.

Result  

On this project, two sets of data were collected. The first set was the pilot data that covered the intended target on each lateral well. The second set was the lateral wellbore data. In the pilot, the operator acquired spectral gamma, resistivity, neutron porosity, density, and dipole acoustic data. Using models built for the area, the petrophysical team produced results that assisted in calibrating and interpreting the PNL in the lateral wells.