As a form of corporate concern to the quality of human resources skillful and competency, Sarulla Operations Ltd gives the opportunity to the expert staff from various departments for knowledge sharing. Guest lecturer become one of the medium. On Thursday, November 7, 2019, Sarulla received an invitation from Pertamina University to fill a course session in the field of Geothermal, with the subject "The Fundamental of Geothermal Fluid". Christovik Simatupang as a Geochemist from the Resources Department delivered an understanding and basic theory of geothermal fluids through the principles of thermodynamics. This lecturer session was held in 2 different classes. The enthusiasm of the participants can be seen from the presence of students and several lecturers who are interested in gaining further understanding from the point of view of practitioners in the industry.