Constructed wetland design for produced water treatment on a colombian petroleum field

Abstract

The development of this paper permits to find and set a new and alternative solution to the big problem that Colombian petroleum fields are facing: Management and Disposal of produced water. Due to the conventional treatment facilities, petroleum companies are spending great amounts of money to treat and dispose petroleum wastewaters. The present project describes a full-scale constructed wetland design proposed as a secondary treatment for a Colombian field produced water.

The design takes into account the physicochemical characteristics of a Colombian field water affluent, represented as organic matter (BOD) and Total Suspended Solids (TSS) oncentrations, according to the main design criteria for the technology, like type and ollutants concentrations, type of wetland, entrance water rate and total area required. Once the type of wetland is selected, the design realizes the principal constraints that affect wetland performance, including operational and maintenance procedures for a future implementation. The design consists in a Horizontal Subsurface flow Constructed Wetland (HSSf CW) with 12 ha of superficial area and 2 ft depth, to treat an average water rate of 678.607 Bbl/day. The HSSf CW consisted on 60 cells of 109,35 x 196,85 ft each, organized in parallel (12) and in series (5). Each cell will be planted with native aquatic macrophytes to enhance purification processes. This grand superficial area design is considered compensated by the low operational and maintenance costs, calculated for a 10-year period. While a conventional treatment system for produced water needs an inversion of US$4.380.338,1 per year, a HSSF CW works with US$23.681,78 for the same time period.