Petrobras has been developing deep water oil fields located in Campos Basin a vanguard subsea project which faces big challenges, one of them wax deposition in production flowlines. So, since 1990, Petrobras has been studying methods 10prevent and remove paraffin-way deposits. Tests of techniques based on chemical inhibition of crystal growth thermo-chemical cleaning (SGN), mechanical cleaning (pigging), electrical heating and thermal insulation were done and the main results obtained at CENPES (Petrobras R & D Center) started to be used in the field in 1993.
This paper presents solutions and procedures which has been used to minimize oil production losses at Campos Basin - Brazil.
The occurence of different types of deposits on pipelines, which affect operational routine in offshore installations, leaded Petrobras to deal with this problem.
In order to evaluate the available methods for preventing and removing these deposits and develop others, the Program on Deepwater Exploitation Systems (PROCAP 2000) has been studying and testing many techniques. Special attention has ken driven to wax prevention and removal methods, for this. is one of the main operational problems faced up.
From the beginning of first phase of Albaccora field exploitation in 1989, it has been noticed that some production flow lines presents organic deposits build-up. This phenomenon happens when paraffin comes out of solution, as the oil reaches the WAP (Wax Appearance Point), due to low sea bottom temperatures.
Although Petrobras is aware about asphaltene, scale and hydrate occurrence, this paper will focus on wax deposition problems, and present difficulties, solutions, procedures adopted by Petrobras in minimizing wax deposit impact on deep water exploitation projects. The use of these techniques imply in additional investment that must be foreseen in the initial phase of the project.
The following aspects will be highlighted:
How to predict the wax deposition
How to solve the problem
Project implications on the development of oil field where wax deposit has been foreseen.
The development of Albaccora, Marlim and Barracuda fields.
PROCAP-2000 is The Petrobras Program on Deepwater Exploitation Systems. The aim of this technological innovation program is the reduction in production costs, increasing productivity in deepwater fields and enabling oil production at water depths over 1000 meters. Production losses due to organic deposition in the flow lines of the wells located far from the production platform can be avoided through studies on the deposition phenomena and establishment of feasible operational techniques. The Flow Assurance in DeepwaterConditions is one of 12 projects included in the scope of PROCAP-2000. (see figure - I)
