Well test (Horner build-up) calculator
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Permeability, skin and radius of investigation from a Horner build-up straight line. Every equation and assumption is listed under the answer.
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Horner build-up
| Permeability k | 48.780 md | |
| Flow capacity kh | 2,439.0 md·ft | |
| Skin s | 5.54 | |
| Pressure drop from skin | 193 psi | |
| Radius of investigation at tp | 4,970 ft |
- k = 162.6 qBμ / (m h); s = 1.151[(p1hr − pwf)/m − log(k/(φμc_t r_w²)) + 3.23]; Δp_skin = 0.869 m s (Horner 1951; Earlougher 1977).
- Assumes radial infinite-acting flow on the straight line you read the slope from, single-phase slightly compressible fluid.
- r_inv = √(k t_p / (948 φ μ c_t)) (Lee 1982).