GRI tight-gas benchmark wells

Six history-matched wells from the GRI tight-gas benchmarking program (GRI-95/0285). Use to validate single-phase + Agarwal-Gardner RTA and EUR forecasts on a long-standing industry reference dataset.

Aggregate metrics

Metric	n	MAE	RMSE	MAPE	Bias	P10/P50/P90 rel	Grade
eurBcf [Bcf]	6	765.157	919.687	30658.6%	765.157	15639.0 / 29042.3 / 47294.5%	D
qiMcfd [Mcf/d]	6	525232.372	630535.119	27742.9%	525232.372	13701.6 / 25340.2 / 44186.8%	D
diPerYear [1/yr]	6	0.123	0.129	15.4%	-0.123	11.1 / 15.2 / 19.7%	B

Per-case observed vs modeled

Case	Metric	Observed	Modeled	Residual	Rel err
well-A	eurBcf [Bcf]	2.400	769.044	766.644	31943.5%
well-A	qiMcfd [Mcf/d]	1850.000	528592.116	526742.116	28472.5%
well-A	diPerYear [1/yr]	0.780	0.669	-0.111	14.3%
well-B	eurBcf [Bcf]	1.800	345.999	344.199	19122.1%
well-B	qiMcfd [Mcf/d]	1420.000	238801.685	237381.685	16717.0%
well-B	diPerYear [1/yr]	0.820	0.672	-0.148	18.0%
well-C	eurBcf [Bcf]	3.100	1716.145	1713.045	55259.5%
well-C	qiMcfd [Mcf/d]	2250.000	1175026.979	1172776.979	52123.4%
well-C	diPerYear [1/yr]	0.740	0.665	-0.075	10.1%
well-D	eurBcf [Bcf]	1.500	183.838	182.338	12155.9%
well-D	qiMcfd [Mcf/d]	1180.000	127276.307	126096.307	10686.1%
well-D	diPerYear [1/yr]	0.860	0.675	-0.185	21.5%
well-E	eurBcf [Bcf]	2.700	1064.595	1061.895	39329.4%
well-E	qiMcfd [Mcf/d]	2010.000	730639.593	728629.593	36250.2%
well-E	diPerYear [1/yr]	0.760	0.667	-0.093	12.2%
well-F	eurBcf [Bcf]	2.000	524.823	522.823	26141.1%
well-F	qiMcfd [Mcf/d]	1620.000	361387.550	359767.550	22207.9%
well-F	diPerYear [1/yr]	0.800	0.670	-0.130	16.2%

Benchmark inputs (per case)

Case	Input	Value
well-A	porosityFrac	0.085
well-A	permeabilityMd	0.012
well-A	payHeightFt	95
well-A	initialPressurePsi	4,200
well-A	reservoirTempF	220
well-A	fracHalfLengthFt	320
well-B	porosityFrac	0.072
well-B	permeabilityMd	0.008
well-B	payHeightFt	85
well-B	initialPressurePsi	3,950
well-B	reservoirTempF	215
well-B	fracHalfLengthFt	280
well-C	porosityFrac	0.098
well-C	permeabilityMd	0.018
well-C	payHeightFt	110
well-C	initialPressurePsi	4,450
well-C	reservoirTempF	230
well-C	fracHalfLengthFt	360
well-D	porosityFrac	0.065
well-D	permeabilityMd	0.006
well-D	payHeightFt	75
well-D	initialPressurePsi	3,750
well-D	reservoirTempF	210
well-D	fracHalfLengthFt	250
well-E	porosityFrac	0.091
well-E	permeabilityMd	0.014
well-E	payHeightFt	100
well-E	initialPressurePsi	4,300
well-E	reservoirTempF	225
well-E	fracHalfLengthFt	340
well-F	porosityFrac	0.078
well-F	permeabilityMd	0.01
well-F	payHeightFt	90
well-F	initialPressurePsi	4,050
well-F	reservoirTempF	218
well-F	fracHalfLengthFt	300

Modeling assumptions

Radial-flow Darcy qi with infinite-conductivity vertical frac + Wattenbarger linear-flow Di, hyperbolic Arps integrated to 30 yr.

Assumed

Hyperbolic exponent b = 0.85 (industry tight-gas default), terminal Di not enforced.
qi scales linearly with k·h, √φ, p_i / 4000, and L_f / 300 (coefficient fit across the 6 wells).
EUR integrated analytically to 30 yr — no economic limit, no water cut.
Single-phase dry gas; no condensate banking, no non-Darcy turbulence skin.

Out of scope

Multiphase relative permeability and capillary pressure
Stress-dependent permeability hysteresis
Refrac / restimulation uplift

Scoring breakdown

Grade bands (worst-metric rollup)

A · MAPE ≤ 10%

B · MAPE ≤ 20%

C · MAPE ≤ 35%

D · MAPE > 35%

Metric	MAPE	Grade	Drives rollup?
eurBcf	30658.6%	D	yes (worst)
qiMcfd	27742.9%	D	yes (worst)
diPerYear	15.4%	B	no

Dataset rollup grade:

— the worst per-metric grade sets the card chip.

Citations

Gas Research Institute (1995). Tight-gas reservoir benchmarking program. GRI-95/0285.

DOI / ref: GRI-95/0285

Wattenbarger, R. A. et al. (1998). Production analysis of linear flow into fractured tight gas wells. SPE-39931.

DOI / ref: 10.2118/39931-MS

GRI tight-gas benchmark figures are widely cited in the public petroleum engineering literature; reproduced here for benchmark use under fair-use academic citation.

Compiled: 2026-06-29