DEPARTAMENTO DE ENGENHARIA NAVAL E OCEÂNICA ESCOLA POLITÉCNICA DA UNIVERSIDADE DE SÃO PAULO

PROJETO II

THIAGO DE JESUS GOMES - 6887136 PIERRE-PAUL LACAS - 8186260 THOMAS DEGERMANN - 8168516 LEANDRO SILVEIRA -

Atividade 1: exemplo de “Albacora Field FPS: another deepwater development offshore Brasil”, S.P. Awad, Petrobras SA.

Professor responsável: Prof. Dr. Claudio Mueller

Q1. O que é o sistema piloto e em que ele consiste?

The pilot system was the corner stone of the project. It was the first part of production of the Albacora field. It was made in the shallower water which was still considered as deep at this time and has for goal to generate a first cash flow to support the research and development of the next steps of the project which are the main goals. The pilot system is made of six wells. There is a manifold which connect all these wells and which can be assisted by divers. The manifold is linked to a FPSO and a monobuoy so that the production can be made directly. The pilot system is known as Albacora Phase and started its production in 1987.

Q2. Descreva sucintamente o que ocorreram nas fases iniciais 1 e 1a .

The fisrt aim of the phase 1 was to generate money in order to pay the futur steps. This was achieved thanks to the bring on stream of 6 wells from 252m to 419m in the shallower water of the Albacora field. The wells were connected to a manifold, the manifold to a monobuoy to a FPSO. This first production unit was connected to a shuttle tanker via an other monobuoy and reached 18 000 bopd and 250 000 std m3 of gas per day. The figure below show the pilot system :

FPSO

well

manifold

The phase 1a consisted in upgrading the pilot system thanks to 8 new wells and linking a second manifold to the FPSO.

The step to the next phase was done by replacing the FPSO with the semisubmersible P-24. Others satellites wells were connected to P-24 well as a second monobuoy reducing the production’s cutdowns during loading operations. In 1993, the production was boosted until 56 250 bopd and 980 000 std m3 of gas per day.

Q3. O que se pode concluir comparando o layout antigo do campo de Albacora com o novo, ao final da fase II ?

The first layout of phase 2 was supposed to use 4 production units connected to 148 wells. Two of them were floating platform and two others wellhead platform whose one assuring process, treatment and offloading. However regarding unsuccessfull drilling in the early 92, high costs of development of the shallower portion and optimized results of horizontal well tied to P-24, the choice of subsea and manifold completion appeared more efficient. The weelhead platforms were cancelled and the two floating units were reduced in one larger operating the treatment onboard and offloading in to a shuttle tanker. Thus the FPSO was connected to 7 horizontal wells instead of 25 conventionally deviated ones. The nothern region of the field was not altered and the existent FPS P-25 was link to the new FPSO. Between February 1991 and December 1994 the previsional cost stepped from 2,7 US$B to 1,2 US$B through re-evaluation of oil reserve corresponding to a cutdown of 220 MMbbl. In the latest layout of phase 2, the FPSO replaces the wellhead platform P-10 and a processing one, using of manifolds connected to the FPSO was chosed to replace the P-24.

To conclude with, the FPSOs seem able to reach the functionality of several platforms in a one, guaranteeing a cut in the investments. Using of subsea manifolds connected to several wells rather than wellhead platforms avoid the problems of the anchorage and the costs of development. The combination of an FPSO tied to manifolds is the most cost effective solution as showed in this article.

Q4: Explique com base no texto as seguintes palavras.

Rig: The machine used to drill a wellbore. In onshore operations, the rig includes virtually everything except living quarters. Major components of the rig include the mud tanks, the mud pumps, the derrick or mast, the drawworks, the Rotary table or topdrive, the drillstring, the power generation equipment and auxiliary equipment. Offshore, the rig includes the same components as onshore, but not those of the vessel or drilling platform itself. The rig is sometimes referred to as the drilling package, particularly offshore.

Appraisal well: a well drilled to further confirm and evaluate the presence of hydrocarbons in a reservoir that has been found by a wildcat well.

Shallower waters: region of little depth, not deep.

Moored: to be secured with lines or anchors.

Q5. Explique com base em outras referências, o que é christmas tree, wellheads e manifolds. Descreva também os tipos de completação e quando cada tipo deve ser usado.

Christmas tree: connected to the weelhead once the well is drilled. It is an assembly of valves, spools, and fittings used for an oil well, gas well, water injection well, water disposal well, gas injection well, condensate well and other types of wells. It was named for its crude resemblance to a decorated tree.

Wellheads: monitors basic phisical parameters of the hole, first link to exterior, contains the Blow Out Preventer. It is the component at the surface of an oil or gas well that provides the structural and pressure-containing interface for the drilling and production equipment. The primary purpose of a wellhead is to provide the suspension point and pressure seals for the casing strings that run from the bottom of the hole sections to the surface pressure control equipment.

Manifolds: used to control arrival of several flows. An arrangement of piping or valves designed to control, distribute and often monitor fluid flow. Manifolds are often configured for specific functions, such as

a choke manifold

used

in

well-control

operations

and

a squeeze

manifold used in squeeze-cementing work. In each case, the functional requirements of the operation have been addressed in the configuration of the manifold and the degree of control and instrumentation required.

The figure below shows the layout of manifold, weelhead and tree.

Chrismas Tree

Manifold

Wellhead, BOP References: http://www.osha.gov/SLTC/etools/oilandgas/glossary_of_terms/glossary_of_terms_c. html http://www.wikipedia.com http://www.ryansrantings.com/

Q6. Quantos poços de exploração são necessarios perfurar antes de se iniciar a produção? Com o que esta relacionado à quantitade necessaria? Cite exemplos de campos de pétroleo, colocando a referência de onde foi tirado.

Before beginning the production of an offshore field of petrol around ten exploration wells are required to perforate. This number depends of the field, the nature of ground, the depth and is of course aleatory. As shown in the following figure there are different types of nature of petrol field. This is illustrating why several research are made to find a field and to be sure that the production would be profitable.

Foto cedida por Institute of Petroleum

Rochas-reservatório de petróleo (vermelho) e gás natural (azul) podem ficar aprisionadas por dobramento (esquerda), falha (meio) ou constrição (direita)

Examples of petrol fields in Brasil:

Guara,

47 explorations wells perforated,

Abaré Oeste,

24 offshore, while 6 reached the

Iracema,

subsalt in Bacia de Santos,

Aruanã.

23 onshore.

This picture illustrates the different types of platform according to the depth. It implies that the exploration phase is different according to the field.

Refenrences: http://www.brasil.gov.br/pac/relatorios/nacionais/8o-balanco/parte-3b-infraestruturaenergetica