_____________________________________________________________________________________________________ *Corresponding author: E-mail: adesinafadairo@gmail.com; British Journal of Applied Science & Technology 17(3): 1-9, 2016, Article no.BJAST.21472 ISSN: 2231-0843, NLM ID: 101664541 SCIENCEDOMAIN international www.sciencedomain.org Formulation and Environmental Impact Evaluation of Walnut and Soya Bean Oil Based Drilling Fluid Fadairo Adesina 1* , Adeyemi Gbadegesin 1 and Olafuyi Olalekan 2 1 Department of Petroleum Engineering, Covenant University, Nigeria. 2 Department of Petroleum Engineering, University of Benin, Nigeria. Authors’ contributions This work was carried out in collaboration between all authors. Author FA designed the study, performed the statistical analysis, wrote the protocol, and wrote the first draft of the manuscript and managed literature searches. Authors FA, AG and OO managed the analyses of the study and literature searches. All authors read and approved the final manuscript. Article Information DOI: 10.9734/BJAST/2016/21472 Editor(s): (1) Verlicchi Paola, Department of Engineering, University of Ferrara, Via Saragat 1, Ferrara, Italy. Reviewers: (1) Ch. V.Subbarao, MVGR College of Engineering, Andhra Pradesh, India. (2) Kazeem, Kolapo Salam, Ladoke Akintola University of Technology, Ogbomosho, Nigeria. (3) Zsuzsanna Czibulya, University of Pécs, Hungary. Complete Peer review History: http://www.sciencedomain.org/review-history/16014 Received 18 th August 2015 Accepted 12 th October 2015 Published 2 nd September 2016 ABSTRACT One of the oil and gas hazard that associated with drilling operation is oil based drilling fluid and its associated cutting disposition. It is highly imperative for policy maker to propagate the use of environmental friendly oil based mud for drilling operation. This paper formulated environmentally friendly oil based mud (using walnut and soya bean plant oil) that can carry out the same function as convectional oil based drilling fluid and equally meeting up with the HSE (Health, safety and environment) standard. Mud laboratory tests were carried out at standard condition on plant oil samples so as to ascertain the rheological properties of the drilling fluid formulations. The synthetic oil based was obtained from drilling company in Nigeria and was used as control experiment. At the end of the experiment, the properties of the walnut and soya beans based mud was compared with industry oil based mud (synthetic oil based mud). All the results were shown to be similar to that of commercial synthetic oil based drilling mud which was gotten from the industry. From the results it can be seen that walnut and soya beans based mud actually gives a less toxic, better rheological properties, requires less waste disposal costs, hence making them more economically and technically viable for oil and gas drilling operation. Original Research Article