D Drilling conducted at JV-20 well is to increase absorption points from fieldP which aims to increase oil production in the field. The JV-20 well began drillingon 23 February 2018 and was drilled horizontally with a total depth of 12125 feetMD target. When drilling in both wells, there is a drilling problem that is lostcirculation or loss of drilling mud circulation. This Lost Circulation is an eventwhere the loss of some or all of the drilling mud into the formation. This lostcirculation problem can occur due to two reasons, the pressure factor or theformation factor itself. When viewed from the pressure factor, the pressure thataffects the occurrence of lost circulation is hydrostatic pressure, formationpressure, and formation fracture pressure. If the hydrostatic pressure is greaterthan the formation pressure, there will be lost circulation. When viewed from theformation factor, there are several formations that cause lost circulation likeformations that have caves, formations that have large grains, and formationsthat have faults or fractures. If you encounter a formation that has thecharacteristics as mentioned above, lost circulation will easily occur. Theproblem of lost circulation often occurs in field LA. For JV-20 well itself there iseight times lost circulation with partial and total loss type. Lost circulation thatoccurs in JV-20 well is on the 17-½” and 18-½” drilling route. Based on dataobservations and evaluation results, the factor that causes lost circulation is thepenetrated formation has very large porosity and permeability. The method used to overcome lost circulation in JV-20 well is by spot High Viscosity and LostCirculating Material. Lost circulation materials used in JV-20 well are calciumcarbonate (CaCO3), Fracseal and also Kwikseal. The lost circulation handlingcarried out on JV-20 well in LA field in several loss zones was carried out welland successfully, although there were several zones that were required to spotLCM several times to be able to stop the problem of lost circulation at that depth.The LCM used to overcome the occurrence of lost circulation in JV-20 well isFRACSEAL, Kwikseal and CaCo3.