Definitive values that classifies a rock as having “low”, “medium”, and “high” -strength, -hardness, -toughness, and -consolidation?

Question

Question: Are there any widely accepted published values (or ranges) that classifies a rock as having “low” “medium” “high” -strength, -hardness, -toughness, and -consolidation (cementation or cohesion?)?

UCS Background Material: I have come across some papers that have defined what is considered to be “low”, “medium”, “high” strength rocks as characterized by unconfined (uniaxial) compressive strength (UCS). This is what I have found:

• “Due to the unique properties of these quartz arenite sandstone reservoirs high compressive strengths up to 25,000 psi are common,…” (emphasis is mine) (1)

• “In order to define the effect of formation compressive strength on perforator penetration and hole character, various formations in the low-, medium-, and high- strength ranges were acquired for laboratory shot tests.” (emphasis is mine) (2).

The author then lists the rocks tested: low ~ 2000 psi UCS ( Austin chalk), medium ~ 5000 to 7000 psi UCS (Idiana limestone and Berea sandstone), High ~ 11,000+ psi UCS (Carthage limestone)

• “Ultrahigh-strength formations….Oman formations in which UCS varies from 20,000 to 55,000 psi.” (emphasis is mine) (3)

Hardness Background Material: I have seen a paper that has defined the inter-relationship between hardness (using the Brinell hardness number (BHN)) and consolidation, reference 4.

• Loosely consolidated material (BHN 2-4 kg/mm2)

• Friable-to-consolidated material (BHN 10-15 kg/mm2)

Consolidation Background Material: Reference 5 defines what is “unconsolidated” (damp sand), “weakly consolidated” (Saltwash south), and “strongly consolidated” Castlegate, Berea, etc., qualitatively.

• “unconsolidated” = essentially no cohesion e.g. cohesive forces due to friction, granular interlocking and capillary forces.
• “weakly consolidated” = can be failed by forces one can generate with their fingers
• “strongly consolidated” = requires a tool such as an hammer to fail the rock

References:

1. Blosser, W. R. (1995, January 1). An Assessment of Perforating Performance for High Compressive Strength Non-Homogeneous Sandstones. Society of Petroleum Engineers. doi:10.2118/30082-MS
2. Thompson, G. D. (1962, January 1). Effects of Formation Compressive Strength on Perforator Performance. American Petroleum Institute.
3. Mustafa, H. D., Briner, A. P., Jumaat, M. S., Grove, B. M., Atwood, D. C., & Judd, T. C. (2012, January 1). Ultrastrong Formations: Perforating Challenges, Limits, and Optimization. Society of Petroleum Engineers. doi:10.2118/159771-MS
4. Vriezen, P. B., Spijker, A., & van der Vlis, A. C. (1975, January 1). Erosion of Perforation Tunnels in Gas Wells. Society of Petroleum Engineers. doi:10.2118/5661-MS
5. Walton, I. C., Chang, F. F., & Lopez de Cardenas, J. (2004, January 1). Perforation Morphology and the Onset of Sand Production. Society of Petroleum Engineers. doi:10.2118/90123-MS