Why testing in Exploration and Appraisal ?

Flowing period:

• Confirm discovery and productivity

• Clean-up the well and obtain a rate measurement

• Take large volume fluid sample

• Test sand production

Shut-in period: (min. 2 PBU tests)

• Extract information about the well and reservoir performance (skin, turbulence, permeability, initial pressure, heterogeneity, boundaries)

• Investigate reservoir connectivity and proven volume

• Learn about the flow behaviour around the wellbore

• Large scale of investigation (~ 100-1000s feet)

Well testing in exploration and appraisal could point out to reservoir compartmentalization problem. Knowing this type of problem would prevent a field development train-wreck and huge financial losses.

In the uncertain and costly exploration and appraisal environment, it is critical to be prepared and obtain the best quality data, optimize the unique operations with real-time data and learning, and get the most value out of the few data points.

Well Test Services in Exploration and Appraisal

• Well test design:

• • Design test to cover a large range of uncertainty and to achieve the subsurface objectives while minimizing rig time and flared volume,

  • Review existing design to ensure suitable completion design and suitable test duration to achieve objectives and recover deconvolution.

• Monitor operations with QC of data and real-time interpretation

  • Ensure best quality data,

  • Optimize test to achieve objectives and look for more value-adding opportunities at minimum cost,

  • Potentially save few days of rig time and minimize flared volume.

• Post-operation interpretation:

  • Explore all the data, extract all possible solutions and help to integrate the data with other sources of information,

  • Recover and use deconvolution to refine initial pressure, improve understanding of the transient response, add reservoir insights and provide evidence for larger connected volumes,

  • Evaluate minimum connected volume.

• Review past interpretation, re-interpret pressure data using latest techniques and tools (including deconvolution) to extract all possible solutions, increase the value of data, (re)-assess field potential, etc…

• Support alternative permeability testing methods.

Why testing production wells?

• Define initial well performance and assess completion performance in a post well review (well damage, skin elements, permeability, connectivity and initial pressure). Due to the transient response, a combination of rate and pressure measurement points doesn’t define well productivity, in particular for a vertical well in low-mid permeability reservoir, a fractured well or a horizontal well.

• Have a cost-effective surveillance and diagnostic tool thanks to opportunistic shut-ins,

• Monitor and predict performance over time,

• Detect performance deviation and understand its causes,

• Assess well intervention,

• Quality control rate measurement,

• And much more…

Each opportunistic shut-in could be analyzed -provided enough resources and expertise- to understand and monitor well and reservoir performance over time, and detect the causes of performance deviation. Much more information could be extracted and learnt from analyzing your data.

Well Test Services in Production

• Provide surveillance best practices and test procedures for best quality valuable shut-ins.

• For new well delivery:

  • Provide justification for downhole gauge and planned shut-ins,

  • Ensure the data processing system is adapted to pressure transient analysis,

  • Design planned shut-ins to acquire valuable data with minimum duration.

• Use every shut-in as an opportunity to learn:

  • Evaluate reservoir and well production efficiency and completion strategy,

  • Monitor well performance over time: damage, effective permeability, perforation height, horizontal flowing length, frac length and conductivity, pressure support problems, etc…

  • Track reservoir pressure to monitor connectivity and recovery process,

  • Perform multiphase flow analysis.

• Understand performance deviation:

  • Detect water front, predict water breakthrough and support lab-derived relative permeability curves,

  • Detect fluid breakout before the situation becomes irreversible,

  • Spot blockage, sand fill, etc…

  • Avoid a costly well intervention and get a more efficient treatment to successfully target the problem.

• Design data acquisition strategy during an intervention and assess the impact of the well treatment while minimizing the intervention and shut-in time.

• Re-interpret pressure data using latest tools (including deconvolution) and techniques.

Why testing injection wells ?

• It is challenging to understand the performance of a water injection well due to changes in open fracture size with injection pressure, due to possible changes in water temperature (produced vs seawater) and in reservoir pressure, and due to changes in frac conductivity and damage.

• Have a cost-effective surveillance and diagnostic tool thanks to opportunistic shut-ins,

• Understand which factors contribute to change in performance: frac dimension, frac closure, damage, etc…

• Ensure water injection containment in reservoir and no excessive frac growth.

Well test analysis is one of the best tools to understand and monitor the performance of water injectors (and we are not biased…)

Each opportunistic shut-in could be analyzed -provided enough resources and expertise- to understand and monitor well and reservoir performance over time, and detect the causes of performance deviation. Much more information could be extracted and learnt from analyzing your data.

Services

in addition to services on production wells:

• Monitor and improve understanding of injection well performance.

  (multiphase flow, changing open fracture size, long transient response)

• • Detect water/oil interface and cold water front,

  • Monitor fracture size, increase in damage, impact of temperature and pressure,

  • Detect and understand fracturing events,

  • Ensure no excessive frac growth and containment in targeted layer,

  • Assess impact of produced water, cold water flush, stimulation and other interventions.

• Understand causes of performance deviation

  • Detect frac closure, a receding frac height, increase in damage, blockage, sand fill, etc…

• Review previous analysis and re-interpret pressure data using latest tools and techniques.

Why testing frac wells?

• Interpret minifrac for a better frac design,

• Understand fracture length, conductivity and possible damage,

• Assess fracturing operations and check actual versus designed fracture.

Services

• Interpret ACA/minifrac and assist frac engineer,

• Design or review data acquisition strategy to ensure best quality data for well test analysis,

• Post evaluation of frac treatment, resulting in frac length, conductivity, frac damage, reservoir permeability, etc…

• Monitor frac length, conductivity and damage over time.