Paper Title
Utilization of Natural Rubber Latex as Additives in Drilling Mud

Abstract
This investigation relates to an improved water-based mud fluid composition by mixing with natural rubber latex (NRL) as additives. The objective of this study is to investigate rheological properties of water base drilling mud mixed with NRL. The methodology was analyzed by adding 0.3, 0.5 and 1 percent of weight by volume of NRL at 30, 45, 60 and 80°C, respectively. The rheological properties of drilling mud mixed with NRL included viscosity, gel strength, filtration, and pH, which tested based on the API RP 13B-1 standard. The test results indicated that the apparent viscosity, plastic viscosity, yield point, and gel strength of drilling mud mixed with NRL increased with the increment of NRL concentration and temperature. The API fluid loss values of drilling mud mixed with 0.3, 0.5 and 1 percent NRL concentration are better than the base drilling mud as 6, 13 and 19 percent respectively improvement. Value of pH ranged from 10.0-10.2 which it can minimize corrosion problem of steel in drilling fluid circulation process. The cost for the water-based mud mixed with NRL is cheaper than of base mud with another commercial additive. The inexpensive NRL is an ecological friendly biopolymer, which is easily affordable in Thailand. Keywords - Drilling mud, Viscosifier, API fluid loss, Natural rubber latex, Rheology