Oil exploration and discovery in the basement rocks of Bach Ho field: Documentation, facts and lessons

During the 40 years of operation and development (1981 - 2021), the Vietnam - Russia Joint Venture "Vietsovpetro" has witnessed many historical milestones, but the discovery of industrial oil for the first time from the fractured and weathered granite basement at exploration well BH-6 on 11 May 1987 is the most important one. From the first oil in the basement rock of Bach Ho field, Vietsovpetro consecutively discovered industrial oil in other fields in its area of operation, such as Dong Bac Rong (1991), Dong Nam Rong (1995), Nam Rong (2005), Nam Trung Tam Rong (2006), etc. At the beginning of 2018, the 2P (P1+P2) oil reserve from the basement rock accounted for 74% of Vietsovpetro's total balanced reserves at that time. As of 1 October 2021, the total oil produced from the basement reached 235 million m3 (195 million tons), accounting for 86% of Vietsovpetro's total oil output. Being encouraged by the success and experience of Vietsovpetro, other domestic and foreign oil and gas companies (PVEP, JVPC, Talisman, and Petronas, etc.) have explored and discovered oil and gas from the granite basement and put the fields of Rang Dong, Su Tu Den, Hong Ngoc, and Hai Su Den, etc. into operation. This fact has, at the same time, created a strong attraction for domestic and foreign investors, making important contributions to the rapid development of Vietnam's oil and gas industry which was still very young at the time. The above-mentioned shows that it is time to study data and documents, draw lessons from success and failure gained during the 40 years of basement exploration. The outcomes should be used as a basis to formulate an appropriate exploration strategy for Vietsovpetro in the coming decades with strong fluctuations in the oil and gas market expected, and the inevitable depletion of non-renewable resources worldwide.