Implications of Reduced Heating of Heavy Crude Pipeline on Pump Lubrication Systems

OCP Ecuador S.A. was designed for transporting heavy crude oil from the Ecuadorian Amazonian forest to the Pacific Ocean, crossing the Andes (highest point @ 4060 masl). OCP have four pumping stations PS1, PS2, PS3, PS4 located across the first 182km. Main pumps were designed with an inherent product circulation from pressure connection via orifice to mechanical seal (API Plan 11) for lubricating and cooling. In order to achieve required viscosity, crude oil from the main line must be heated. Low sulfur crude oil (LSCO) is burned for this purpose. In order to optimize fuel consumption, some efforts were conducted since 2006. The first aim was to increase feed rate of lubricating oil, in order to extend the viscosity within seals up to 700cP. This modification resulted in considerable heat exchange depletion, representing about 50% of costs reduction related to reduce heating of crude oil in the main line. Since 2009, there were some adverse scenarios, which forced the company to seek more and better ways to optimize the fuel oil consumption. These scenarios were: • The continued decline in the quality of crude oil delivered by the shippers quality from shippers. Reduced quality was seen as a threat to the integrity of mechanical seals. • Unavailability of LSCO in the country, • The under-utilization of transport capacity due to low volumes of oil (30% of its capacity). Facing this situation, OCP decided to analyze the technical and economic feasibility of operating without heating oil, in an intermediate pump station (PS3: KP 148 @ 1800 masl). This pump station, at the time of the study, was operated heating crude oil. The greatest difficulty in achieving the goal of reducing heating oil was the maximum viscosity that mechanical seals could withstand, without affecting its integrity. To mitigate this threat, an API plan 32 was designed and implemented in PS3. Simultaneously, the organization was evaluating the possibility of installing a similar system in PS4, where climatic conditions are more adverse than PS3. Based on thermal models and after risk evaluation and cost benefit analysis, OCP decided to run operations accepting the risk of potential damage to the seals in PS4. At the moment, OCP Ecuador S.A. is operated without heating crude oil and API plan 32 was placed on standby, reducing considerably the operating costs. This paper is intended to share the learned lessons, some actions taken; obstacles faced up as well as achieved results in this cost reduction effort.