Correction to: Probabilistic estimation of hydraulic fracture half-lengths: validating the Gaussian pressure-transient method with the traditional rate transient analysis-method (Wolfcamp case study) (Journal of Petroleum Exploration and Production Technology, (2023), 13, 12, (2475-2489), 10.1007/s13202-023-01680-9)

Alvayed, D., Khalid, M. S. A., Dafaalla, M., Ali, A., Ibrahim, A. F., & Weijermars, R. (2023). Probabilistic estimation of hydraulic fracture half-lengths: validating the Gaussian pressure-transient method with the traditional rate transient analysis-method (Wolfcamp case study). Journal of Petroleum Exploration and Production Technology, 1–16. The original version of this article unfortunately contained serious typographical errors due to mishaps in the proof-printing process. This correction article aims to rectify these errors in order to do justice to our original work, which was executed with the greatest care for detail and accuracy. Point 1: Due to two distracting errors in the Abstract, the correct Abstract is given here in full below: Abstract—Despite significant advancements in geomodelling technologies, accurately estimating hydraulic fracture half-length remains a challenging task. This paper introduces a detailed estimation approach using the Gaussian pressure transient (GPT) method, which is relatively new. The GPT method is iterative, ensuring fast convergence and providing reliable estimations of hydraulic fracture half-length based on a predetermined hydraulic diffusivity value obtained from Gaussian decline curve analysis (DCA). To validate the GPT results, production data from two case study wells in the Wolfcamp Shale Formation, located in the Midland Basin of West Texas, are utilized alongside the traditional rate transient analysis (RTA) method. Moreover, the GPT method offers the capability to probabilistically estimate hydraulic fracture half-lengths, presenting two innovative approaches to evaluate the robustness of this newly developed method for both deterministic and probabilistic estimations. The simulation results demonstrate a close correlation between the Gaussian method and micro-seismic fracture half-lengths, with separate confirmation from the classic RTA method. Through the case studies presented in this paper, the GPT method showcases its utility in estimating hydraulic fracture half-lengths for two Wolfcamp case study wells, effectively demonstrating the validity and practical applicability of this novel method. Point 2: Some italicizations and typographical errors in the List of symbols were missing, so the correct List of symbols is given here in full below: Area around the fracture, ft² Oil formation volume factor at reservoir condition, bbl/STB Conversion factor for field units, 0.178108 bbls/ft³ Conversion factor for field units, 1.06235E-14 ft²/mD Conversion factor for field units, 1.67868E-12 psi.day/cPoise Dimensionless reservoir diffusivity Reservoir thickness, ft Matrix permeability, Darcy Total number of fractures Original reservoir pressure, psi Initial production rate, bbl/day Production rate at time t, bbl/day Dimensionless time Fixed distance to the fracture plane (set at 1 ft if using field units), ft Fracture half-length, ft Fluid viscosity, cP Bottom hole pressure, psi Decline curve analysis Gaussian pressure transient Rate Transient Analysis Point 3: Equation (1) on page 2 was published incorrectly, which should be centered and italicized. The correct Eq. (1) is given below. (Formula presented.) Point 4: The text “Formation volume factor (STB/ reservoir bbls)” in Table 1 on page 4 was published incorrectly, which should be aligned to the left. The correct Table 1 is given below. (Table presented.) PVT mean values for Well 4H and 31H PVT property Well 4H Well 31H Formation volume factor (STB/ reservoir bbls) 1.316 1.324 Viscosity (cPoise) 0.775 0.731 Fluid type Black oil Black oil Point 5: Equation (3) on page 6 was published incorrectly which should be centered and italicized, and use (Formula presented.) instead of BHP. The correct Eq. (3) is given below. (Formula presented.) Point 6: In the sentence beginning with “BHP represents bottom…” on page 6, the symbol “BHP” was published incorrectly, which should be replaced with (Formula presented.). The corrected part of the sentence is given below. “ (Formula presented.) represents bottom hole pressure” Point 7: Equation (4) on page 6 was published incorrectly, which should be centered and italicized. The correct Eq. (4) is given below. (Formula presented.) Point 8: The two symbols “ (Formula presented.) ” in Table 3 on page 7 were published incorrectly, which should be in italics. The correct Table 3 is given below. (Table presented.) Average fracture half-length (Formula presented.) from micro-seismic for Wells 4H, 44H, 45H, and 46H Well Avg (Formula presented.) (ft) Cluster number Total volume of fluid (gallons) Total proppant (lb) 4H 570 99 219,000 200,000 31H N/A 136 316,218 335,851 44H 638 > 75 300,000 333,000 45H 334.5 > 75 304,000 337,000 46H 295 143 303,000 336,000 Avg 45 and 46 314.75 Point 9: Equation (5) on page 7 was published incorrectly which should be centered and italicized, and replace BHP by (Formula presented.). The correct Eq. (5) is given below. (Formula presented.) Point 10: In the sentence beginning with “The conversion factors (Formula presented.) are needed…” on page 7, the three symbols “ (Formula presented.) ” were published incorrectly, which should be in italicized. The correct symbols are given below. “ (Formula presented.) ” Point 11: In the sentence beginning with “Rearranging Eq. (5) yields Eq. (6). Which was…” on page 7, the text. “Which” was published incorrectly. The dot should be removed, and the text “Which” should not be capitalized. The correct sentence is given below. “Rearranging Eq. (5) yields Eq. (6), which was used in this study to stochastically model the fracture half-length:” Point 12: The symbol “BHP” on page 7 was published incorrectly, which should be replaced with (Formula presented.).