Cooperation on Multiphase Flow Pumping
Authors: Caetano E.F. , Silva RM. , da Silva R.G. , Camargo R.M.T. , Rohlfing G. 
Published: October 2008

PETROBRAS (Brazil) and BORNEMANN PUMPEN (Germany) are since 1993 working on this route development under a Technological Cooperation Agreement. This Cooperation has allowed, among other aspects, the development, through testing, of a multiphase flow pump prototype. The pump is a volumetric type (twin-screws) and able to operate under several multiphase flow conditions, whereas the Gas Void Fraction (GVF) reaches values as high as 95 % in volume, at the pump suction conditions. The referred tests have been conducted at the recent conceived and built PETROBRAS Test Site for Multiphase Equipment, located at the PETROBRAS' E&P-SEAL area, in Atalaia, city of Aracaju. This onshore test site allows performing highly representative tests when compared with actual production installations. This paper presents the major characteristics of this technological route and focus on the tested multiphase pump description, its programmed commissioning, performance and endurance campaigns, including the results acquired up to date and the mentioned Cooperation basis and produced results.

Introduction

Among the 29 Sedimentary Basins encountered in Brazil, besides the exploration efforts on all of them, PETROBRAS has fortunately reached production in 9 ones. Produces around 7,200 wells and has reached a total production close to 143 × 103 m3/d, - here approximately 75 % comes from offshore areas, whereas 30 % of the total comes from water depths WD) beyond 400 m. The offshore wells, stretching throughout almost the entire Brazilian coast, are produced with 91 Stationary Production Units (SPU), i.e., platforms (several types), floating vessels etc. In terms of future potential discoveries, the Company exploratory play analysis indicates values up to 65 % for the discoveries in offshore deep areas.

At the moment, PETROBRAS produces in water depths crossing the 1,000 m WD (world record holder), while recently discovered fields are stretching out beyond the 2,000 m of WD boundary. Thus, aiming at the continuos success in such area, PETROBRAS established (1992) a corporate R&D program, PROCAP. -2000' (Technological Innovation program on Deep Water Exploitation Systems). This Program is pursuing the development of several innovative technologies that shall lead the Company to the full technological capability to exploit oil fields at WD up to the 2,000 meters boundary and making use of technologies that shall introduce strong changes on the current deep-water production way. Table 1 shows the PROCAP-2000 Project Portfolio which translates the composing strategic systemic projects being developed in the program.

Among the innovative technological routes composing such program, one shall find the Multiphase Flow Pumping, especially dedicated to the subsea scenario, but aware that onshore and offshore topside applications shall happen even sooner as a collateral benefit of such underway effort.

Late 1994, PETROBRAS conclusions were reached for a internal study that pursued the prediction of possible impacts resulting from the application of this technology, among others, on the deep water giant oil fields, as well as, a prediction of the main technological developments found as required for the conceptions to become available to the Company usage. Caetano et a12 reported such study and its main conclusions.