Formation Evaluation in the Devonian Shale

Campbell, R.L.; Truman, R.B.

doi:10.2118/15212-ms

Cited by 12 publications

(2 citation statements)

References 4 publications

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“…These measurements provide virtually no information on natural fractures, mineralogy, or stress which can impact hydraulic fracturing and overall completion efficiency. 'Hot' gamma ray zones are typically driven by kerogen content and often do not posses mechanical, detailed petrophysical, and other properties which make them conducive to obtaining complex hydraulic fracture systems from each perforation cluster (Campbell and Truman, 1986; Baree and Gilbert, 2009). Furthermore, these high gamma ray zones are often more ductile causing hydraulic fracture initiation problems and reducing retained hydraulic fracture conductivity (Baree and Gilbert, 2009).…”

Section: Fig 3 -Gamma Ray Steering Disparities When Drilling Horizonmentioning

confidence: 99%

“…Perforation clusters and hydraulic fracture staging can be intelligently selected based upon LWD data. 4. HFM data can be used to determine microseismic fracture fairway width and height and PL data can be used to determine which layers and rock types contribute most to production further refining the target to land the lateral in.…”

Section: Integration -Deriving Additional Value Integrationmentioning

confidence: 99%

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Unlocking the Shale Mystery: How Lateral Measurements and Well Placement Impact Completions and Resultant Production

Baihly

Malpani

Edwards³

et al. 2010

All Days

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Across many shale plays in North America, operators ask why production performance disparities exist among horizontal wells. For example, even though drilling and completion practices of a neighboring operator may be mimicked, significantly different production results are frequently observed. Several hypotheses have been presented on the subject with little consensus. In most of these wells, formation evaluation in the lateral section is limited to gamma ray. Using a single curve to model the structure leads to multiple solutions with no way to determine which one is correct. Accordingly, large uncertainties may exist in: 1) determining the relative geologic position of the wellbore, 2) placing perforation clusters, and 3) selecting the appropriate staging design and stimulation treatment for the resulting well placement.To produce wells that perform to their maximum potential, it is fundamentally necessary to understand both the placement of the lateral in the reservoir and the placement of the perforations in the lateral. To optimize these placements, some measurements must be taken in the lateral. Obviously, the value of understanding where to locate the lateral and the perforations must be greater than both the direct costs associated with taking these measurements and the risk weighted costs associated with deploying tools in the lateral. A way to acquire this information while mitigating many of the aforementioned concerns is logging while drilling (LWD). Some of the measurements that LWD can capture along shale laterals include borehole/azimuthal images, stress, and mineralogy. With these comprehensive LWD measurements, not only can the captured data be taken for future completion design and analysis, they can also be used while drilling the lateral to steer the wellbore towards a desired target more accurately than gamma ray only. This paper focuses on how lateral LWD measurements impact well placement, perforation selection, hydraulic fracture stage spacing, completion design, resultant production, and subsequent economics of horizontal shale wells. Practical LWD examples from the Eagle Ford and Woodford Shale plays are presented, along with their impact on the aforementioned subjects.In this paper principles of using LWD measurements and interpretation in a field development plan are described, including relating LWD data to additional functions such as completion design, microseismic hydraulic fracture monitoring, production monitoring, and production logging. Ideas on how to optimize the amount and type of LWD measurements are proposed. Lastly, the paper will examine the impact of LWD measurements on the overall economics of horizontal shale wells.

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Section: Fig 3 -Gamma Ray Steering Disparities When Drilling Horizonmentioning

confidence: 99%

Section: Integration -Deriving Additional Value Integrationmentioning

confidence: 99%

Unlocking the Shale Mystery: How Lateral Measurements and Well Placement Impact Completions and Resultant Production

Baihly

Malpani

Edwards³

et al. 2010

All Days

View full text Add to dashboard Cite

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7. Bibliography

1989

Developments in Petroleum Science

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The petrophysics of shale gas reservoirs: Technical challenges and pragmatic solutions

Bust¹,

Majid²,

Oletu³

et al. 2013

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The host rocks of shale gas accumulations act as source, seal and reservoir. They are characterized by complex pore systems with ultra-low to low interparticle permeability and low to moderate porosity. The word ‘shale’ is used in the sense of a geological formation rather than a lithology, so shale gas reservoirs can show marked variations in rock type from claystones, marlstones and mudstones to sandstone and carbonate lithological ‘sweet spots’. The pore space includes both intergranular and intrakerogen porosity. The density of natural fractures varies markedly, and pore throat connectivity is relatively ineffective. Moreover, in-situ gas pore volume has to take account of both free and adsorbed gas, an evaluation exercise that is complicated by pronounced variations in water salinity. All these characteristics present major challenges to the process of petrophysical evaluation. The petrophysical responses to these issues are severalfold. First, a broader calibrating database of core measurements is required at key wells, especially as regards mineralogy, porosity and permeability data, shale/mudstone sample analyses, total organic carbon, gas desorption isotherms, and the analysis of extracted formation waters. Second, at least in the key wells, an extended suite of logs should include an elemental analysis log, magnetic resonance imager, electrical micro-imager, and a dipole sonic log. These databases lead to a rock-typing scheme that takes better account of dynamic properties and fracturability. They also allow reservoir partitioning based on exclusivity of empirical interpretative algorithms, e.g. quartz content vs. producibility. These responses comprise key elements of a functional petrophysical system that encompasses fit-for-purpose interpretation methods, such as a pseudo-Archie approach, i.e. the application of the Archie equations with non-intrinsic exponents. This system is presented as a workflow for application in shale gas reservoirs, for which bulk density retains a major influence on computed gas in place. The benefits of this approach are especially strong in reserves reporting of these unconventional gas reservoirs.

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Formation Evaluation in the Devonian Shale

Cited by 12 publications

References 4 publications

Unlocking the Shale Mystery: How Lateral Measurements and Well Placement Impact Completions and Resultant Production

Unlocking the Shale Mystery: How Lateral Measurements and Well Placement Impact Completions and Resultant Production

7. Bibliography

The petrophysics of shale gas reservoirs: Technical challenges and pragmatic solutions

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