Bin: Particle Size Classification, Proppant Storage, and Geostatistical Reservoir Analysis

Key Takeaways

• Proppant size bins: API 19C sieve analysis and quality control: API RP 19C defines the standardized sieve analysis procedure for hydraulic fracturing proppants and gravel-pack media. The test procedure: a representative sample (approximately 100 g for dry sieve analysis) is loaded on a stack of nested sieves arranged from coarse (top) to fine (bottom), then mechanically shaken for 10 minutes on a Ro-Tap shaker (278 RPM circular, 150 RPM tapping); the mass retained on each sieve is weighed and expressed as a percentage of the total sample weight. The size bins defined by the sieves determine whether the proppant meets API 19C specification: the "main" bin between the two controlling sieves must contain at least 90% of the mass; the "fines" bin below the lower sieve must contain no more than 1% (fines damage proppant pack conductivity by filling void space); and the "oversize" bin above the upper sieve must contain no more than 0.1%. Common WCSB frac proppant size bins: 20/40 mesh (coarse, 0.420-0.841 mm, for moderate-closure-stress Montney at 35-55 MPa effective closure); 30/50 mesh (medium, 0.297-0.595 mm, standard for most Montney and Duvernay stages); 40/70 mesh (fine, 0.212-0.420 mm, for high-closure-stress deeper Duvernay above 60 MPa); and 100 mesh (very fine, passing 0.149 mm sieve, used as a far-field diverter in near-wellbore complex fracture networks). Each size bin has a different pack conductivity (Darcy-mD-ft) measured per API 19D at simulated closure stress — 20/40 achieves approximately 3,000 mD-ft at 35 MPa versus 1,500 mD-ft for 40/70 at the same stress, justifying the coarser size bin in shallower Montney intervals where closure stress permits.
• Physical frac sand bins and proppant logistics on a Montney spread: A Montney multi-well pad frac operation (6 wells, 30 stages/well, 200-400 tonnes of proppant per stage) requires delivery and staging of approximately 36,000-72,000 tonnes of proppant before and during pumping, managed through a fleet of pneumatic transport silos (bins) parked adjacent to the frac blender. Standard pneumatic transport silo specifications for WCSB operations: capacity 400-450 metric tonnes (MT), height 14-16 m, diameter 3.5 m, carbon steel construction with fluidizing cone bottom, rated to 15 psi maximum pneumatic transfer pressure, with a load cell array for continuous weight monitoring. A 30-stage frac program consuming 300 tonnes/stage requires 9,000 tonnes total per well, or 54,000 tonnes for a 6-well pad program — approximately 1,600 truck trips of 34 tonne capacity to deliver all proppant, typically staged as 18-20 silos parked on the frac spread providing approximately 7,200-9,000 MT of on-site buffer capacity, with continuous pneumatic truck deliveries running 24 hours/day during the frac program. Bin-level monitoring via load cells allows the frac data acquisition system to calculate real-time proppant consumption per stage and compare against the designed proppant schedule, triggering a blender hold if bin weight falls below the calculated minimum required for the remaining stage volume — a critical safety function that prevents running out of proppant during a stage, which can result in proppant-free sections of the hydraulic fracture and loss of fracture conductivity.
• Cuttings bin at the shale shaker: waste management on WCSB well sites: In drilling operations, "bin" refers to the v-bottom skip or rectangular steel container (capacity 3-8 m³) positioned beneath the shale shaker deck to collect drill cuttings as they are discharged from the vibrating screens. On a WCSB surface hole (typically 17-1/2 inch bit, 450-600 m depth), the shaker cuttings bin collects approximately 4-8 m³ of cuttings per hour during active drilling — at 20 m/hr drill rate through a 17-1/2 inch wellbore, cuttings volume generation is approximately 1.0 m³/m × 20 m/hr = 20 m³/hr of bulk cuttings (including 30% porosity in the bulk volume), requiring a bin change-out every 15-25 minutes during fast drilling. In Alberta, cuttings bin management is governed by AER Directive 050 (Drilling Waste Management), which requires that all water-based mud cuttings from surface holes meeting the Class I drilling waste specifications (less than 1% by weight hydrocarbons, TDS below 4,000 mg/L in eluted water) be disposed at an approved cuttings pit or landfill facility — typically a bi-weekly cuttings bin haul from the well site using a roll-off bin truck, with the bin weighed at a certified scale and the manifest recorded in the operator's Directive 050 waste volume tracking system. For oil-based mud (OBM) or synthetic-based mud (SBM) cuttings, the more stringent Directive 050 Class II requirements apply, typically mandating thermal desorption or bioremediation treatment rather than direct land disposal.
• Histogram bin width selection in reservoir permeability analysis: Reservoir engineers use histogram bins to analyze the distribution of core-measured or log-derived permeability across a formation, with the choice of bin width critically affecting the visual interpretation and statistical conclusions. For a Pembina Cardium core dataset with permeabilities ranging from 0.01 mD to 500 mD across 340 core plugs, using linear bin width (e.g., 50 mD bins from 0 to 500 mD) creates a histogram with 98% of data in the first bin (0-50 mD) and nearly empty bins above 100 mD — the distribution appears as a near-vertical spike that reveals nothing about the internal structure of the low-permeability population. Using logarithmic bin width (0.5 log-decade intervals: 0.01-0.032, 0.032-0.10, 0.10-0.32, 0.32-1.0 mD, etc.) spreads the data across visually interpretable bins that reveal the bimodal or lognormal nature of the permeability distribution — the standard approach for all reservoir permeability datasets spanning more than two orders of magnitude. The Dykstra-Parsons coefficient (VDP), which quantifies permeability heterogeneity and directly controls the sweep efficiency and recovery factor of a waterflood, is calculated from the log-normal permeability distribution using these histogram bins: VDP = (k50 - k84.1) / k50, where k50 and k84.1 are the permeabilities at the 50th and 84.1th percentiles on the cumulative log-normal permeability plot, with VDP = 0 indicating perfectly uniform permeability and VDP → 1.0 indicating extreme heterogeneity approaching a delta-function distribution.
• Gravel-pack media bins: sieve sizing for production completions: Gravel-pack completions in unconsolidated WCSB formations (Cold Lake Clearwater, Peace River sands, and some shallow Viking pools) use carefully graded gravel placed around a screen in the perforated interval to prevent sand production while maintaining high inflow conductivity. The gravel size is selected relative to the formation sand grain size distribution measured from core sieve analysis: the target gravel size bin is typically 5-6 times the D50 of the formation sand (the median grain size bin), following the Coberly-Wagner criterion for screen slot size and gravel size selection. For a Cold Lake Clearwater formation with D50 of 0.18 mm (medium sand), the target gravel size bin is 0.18 × 5 = 0.90 mm, corresponding approximately to 16/30 US mesh gravel (0.595-1.19 mm bin); the screen slot size is set at 0.5 to 0.7 times the D10 of the gravel size bin (the fine end of the gravel distribution) to retain gravel while preventing fine gravel from bridging across the slot. API 19D gravel-pack testing at reservoir closure stress (typically 8-15 MPa in shallow Cold Lake operations) verifies that the selected gravel size bin maintains the minimum 40 Darcy conductivity required for a commercial gravel-pack completion performance ratio (PR) above 0.90 (90% of open-hole productivity).