Extraction of lignin from black liquor for application as loss circulation material in drilling mud: article

Well exploration and drilling are the most expensive process in oil and gas industry. Materials that are used abundantly during drilling process are loss circulation material (LCM). It is used to prevent the loss of drilling fluid into natural or induced fracture. Black liquor (BL) is the liquid by-product of the kraft pulp process. This waste could be disastrous if release to natural water stream because it has very high pH value. The valuable lignin contain in BL are abundant and there are reported studies that it can be used as LCM. In this research, the lignin extracted from BL will be used directly as LCM in drilling mud. The extraction was conducted based on Taguchi experimental design approach with three parameters and two levels. The parameters are types of acid, temperature and pH value. Using Signal-to-noise (S/N) ratio of Taguchi, the most impactful parameter for extraction is the types of acid while the least is temperature. The rheological analysis of the water based drilling mud after formulated with extracted lignin (EL) using viscometer shows that adding EL into the mud changed it rheology but in acceptable range according to American Petroleum Index (API). The fluid loss test using API Filter Press from the mud with EL decrease up to 33% compared to basic mud. The EL from BL are accepted to be used as LCM.