BUI VIET DUC; NGO VAN TU; BUI TRONG KHAI; DANG CUA; BUI VIET PHUONG; VU VAN HUNG; HOANG HONG LINH; BUI VAN THOM; NGUYEN XUAN THAO. Research and field-trial of “KCl-Protex Sta” drilling mud system and using Protex Sta in combination with CFL-AKK-KCl-PAG, KGAC drilling mud systems to improve well drilling efficiency . Petrovietnam Journal, v. 4, p. 23-29, 29 Apr. 2019.