P20 Series Preseparation Hydrocyclone

 

PSEP 3D

Overview

Cyclotech’s P20 Series Preseparation Hydrocyclone liner is designed to provide a compact solution to separate bulk water from a crude oil stream.  Typical preseparation applications are as follows:
  • To debottleneck a water constrained process facility by removing upstream bulk water upstream;
  • Remote wellsite bulk water removal to debottleneck the capacity constrained flowlines to a central gathering centre;
  • To act as a “pre-deoiling” hydrocyclone for applications where there is an ingress of oil from the production separator to the Produced Water Treatment system which is high enough to overload a single stage Deoiling Hydrocyclone.
In all cases, the separated water from the P20 Series Preseparation Hydrocyclone is then generally routed to a second stage B20 Series Deoiling hydrocyclone and degassing vessel or CFU for further treatment to allow local disposal. These two or three stage systems are known as Partial Processing Systems. When compared to conventional gravity separator options, these systems are compact, light weight, efficient and reliable, all critical factors if they are to be deployed at remote well sites for example.
 
There are two main criteria which must be satisfied to ensure technical viability:
  • The inlet oil water emulsion must be water continuous. This implies that typically the water cut must be above 60% although both water continuous and oil continuous emulsions can exist well above and below this level.  Preseparation, or more correctly Dewatering, is not generally viable for oil continuous oil/water emulsions.  The only exception to this is hot condensate water-in-oil emulsions where the condensate viscosity is very low; 
  • Some gas can be accommodated without effecting the separation performance although a bulk gas separation system can be installed upstream of the preseparation system for applications with high inlet Gas Void Fractions.
Although dependent on the inlet water cut, it is possible to separate up to 98% of the inlet bulk water using a P20 series Preseparation Hydrocyclone system. This is dependent of the stability and magnitude of the inlet water cut and the emulsion stability.
 

Principle of Operation

A hydrocyclone has no moving parts and achieves liquid/liquid separation by virtue of a pressure drop across the unit. Oily water is forced under pressure into the inlet section of the liner via a tangential inlet port. This, together with narrow cyclone diameter, causes the fluid to spin at high velocity, which creates a high g radial acceleration field. Oil, the less dense liquid, is forced to the axial centre of the hydrocyclone to form an oil core. Through internal hydrodynamic forces and external differential pressure control, this oil core is removed counter currently via an axial port adjacent to the inlet while the water flow is discharged from the cyclone tail pipe.
 

Hydrocyclone Liner Design

The hydrocyclone geometry is critical to achieve optimal separation performance. Preseparation hydrocyclone designs cannot be scaled up and so the P20 hydrocyclone liners are manifolded together in a common vessel to achieve the required system flowrate. The ultra-slim external dimensions of the P20 Series liner has been designed to provide market leading liner packing efficiency to maximize process throughput within a given vessel without compromising on performance.
 
Cyclotech P20 Preseparation Hydrocyclone liners are most commonly manufactured in Duplex Stainless Steel. For erosive applications, Cyclotech offers liners with all inlet and taper internal surfaces, manufactured from a range of wear resistant materials. These include Stellite 6, Tungsten Carbide or Reaction Bonded Silicon Carbide, an advanced ceramic that will provide a wear live of up to 10 times that of a standard Duplex liner.
 

High Turndown Vessel (HTD) Design

For applications requiring very high turndown, Cyclotech offers its HTD compartmentalised vessel design. Internal baffles are used to divide the vessel into either two or more separate subcompartments. Each compartment can be switched in or out of service using external valving. This operation can be manual or automated, the latter particulary prudent for applications with a highly variable flowrate. The Cyclotech HTD design has considerable benefits over traditional methods to increase turndown as it removes the need for either blanking liners or multiple vessels. In a typical installation, the Cyclotech HTD design can increase the turndown from 3:1 (a typical value for a conventionally designed vessels) to over 10:1 for a two compartment HTD vessel and over 50:1 for a three compartment HTD vessel. 
PTTEP LKU PP PTTEP LKU PP2
 

System Design

Given the range of inlet process variables (water cut, flowrate, transients), Cyclotech recommend that these two or three stage Partial Processing systems are supplied as automated packaged systems.  Standard pressure vessel designs are available at most design pressures and temperatures and to most common design codes such as PD5500, ASME VIII, AS1210 or GOST-R. Materials of construction range from standard and low temperature carbon steels through to most stainless steels such as Duplex, 6Mo, Super Duplex, 625, 825 and other alloy steels. 
Shell PP Shell PP2
 

Hydrocyclone Spares

Cyclotech specialise in the supply of spare like for like hydrocyclone liners and seal kits for third party systems. The Cyclotech P20 Series Preseparation Hydrocyclone liners can be adapted to directly fit into third party vessels without the requirement for any modification to the existing vessel, although the installed base of third party preseparation systems is very small. Operators would find the benefits include greater performance, more wear resistant material options and greater cost effectiveness.
 

Field Testing.

Cyclotech has a range of P20 and B20 Series single liner test units (up to 900#), which can be used to determine the performance of a P20 Preseparation / B20 Deoiling hydrocyclone based Paratial Processing system on live fluids. These test units are compact, require no utilities and come complete with all required valving, instrumentation and hosing. Cyclotech can also perform a full oil drop size characterisation of the existing process streams as part of these performance trials.
PP FTU 1 The Talcinator
 
Please contact us if :
  • Your process is water capacity constrained.
  • Your flowlines from your well sites to the central gathering facility are capacity constrained
  • You are planning to increase the capacity of your existing Produced Water Treatment system.
  • You require spares for your existing third party Partial Processing system.