first worldwide esp well test in ultra deep water- pbr

First Worldwide ESP Well Test in Ultra Deep WaterFirst Worldwide ESP Well Test in Ultra Deep WaterFirst Worldwide ESP Well Test in Ultra Deep WaterFirst Worldwide ESP Well Test in Ultra Deep Water Artificial Lift Services

V. M. Oliveira - Schlumberger

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abstract must contain conspicuous acknowledgement of where and by whom the

paper was presented.

AbstractAbstractAbstractAbstract

With analysts predicting that todays high oil prices will be

with us for the next year (WEC/WEA report Nov 2005), the

time is right to exploit these reserves. However, cost

efficiency and risk reduction are key concerns in this

environment, requiring special processes and advanced

technologies to bring these reserves on line in budget and to

plan. Given this context, efficient testing and reservoir

characterization procedures assume increasing importance

to meet bottom line production targets.

In Brazil, it is estimated that the heavy oil reserves sitting

offshore in shallow, deep and ultradeep waters would make

the country a self-sufficient oil producer and, recently

announced, an exporter. The technical challenges of

producing and lifting heavy oil are compounded, however, by

the demands and expense of offshore production.

Following a brief understand of Brazilian scenario, this paper

shows how Schlumberger performed to accomplish with

Petrobras and partners objectives related to Xerelete Field

and the operational process made to reach a worldwide

record by using Electrical Submersible Pump as artificial lift

method to test a heavy oil well in ultra deep water.

ObjectivesObjectivesObjectivesObjectives

Conclusive evaluation of Xerelete field and reservoir

characterization

Contribute to the evolution of the Offshore Well Test

concept

Optimize Time and Cost Operation

Continuity of the operation

Optimize the information and analysis

Open new prospects to the Exploratory ESP Well Test

operations in Ultra Deep Water

Consolidate SLB as the leader in Exploratory Well Test

for Heavy Oil Wells

IntroductionIntroductionIntroductionIntroduction

In March 2007, Petrobras Oil Company and partners (Devon

and Total) requested an unscheduled test with ESP-DST to

evaluate the feasibility of a subsea well. It should be a

standard well testing for heavy oil in Brazil if the water depth

was not about 2500m and the pump was not set just above

the seafloor.

To achieve well test objectives for deepwater, heavy oil

reservoirs requires a detailed, integrated testing-design

process. To design and select the most effective production

lifting and surface flow equipment and workflow requires a

thorough reservoir understanding. Obtaining a thorough

reservoir understanding also enables valid procedures to be

designed for safe, environmentally compliant effluent

disposal. This is only possible with accurate downhole data;

therefore, suitability of the downhole and surface well

testing equipment and processes relative to the heavy and

viscous fluids to be tested must be considered.

The Schlumberger full package consisted of all available

equipment and services from downhole to surface, including:

From downhole

DST tools as following

Quantum packer

TFTV (Tubing fill test valve)

SCAR (Sampler Carrier)

DGA (Digital Gauge Adapter)

IRDV (Intelligent Remote Dual Valve)

TSR (Tubing Separation Tool)

SenTREE

RSM (Riser Sealing Mandrel)

ESP into pod with

PumpWatcher Sensor 4C Saphire

Dominator Motor 450HP

Modular Tandem Protectors BPBSL

AGH (Advanced Gas Handler)

Abrasion Resistant Pump GN4000

(mixed flow , 177stg)

Sliding Sleeve

Electrical connector QCI P5000

First Worldwide ESP Well Test in Ultra Deep Water

Vivianne de Oliveira Page 2 of 5 November, 2007

From surface

Artificial lift

SWD (Sinewave Drive) Cabin with

step-up transformer (600kVA) and

sensor surface panel

Surface well test plant

Surface flowhead

Vx multiphase flow meter

Steam exchanger

Separator

Tanks

Transfer pumps

Evergreen burner

PVT Express

STAC (Surface Test Data Acquisition

Cabin) gathered to InterACT

connection

Figure 1: Components used in an integrated well test.

XERELETE PROJECTXERELETE PROJECTXERELETE PROJECTXERELETE PROJECT

The well 3-RJS-648, evaluation plan PA-1-EPB-RJS, is

located in territorial waters of Campos Basin. The Xerelete

field is located partially in the old BC-2 and partially in the

BM-C-14, 155 km southeast of the city from Cabo Frio and 42

km east of the Papa Terra field.

Preliminary geological studies indicate the accumulations

total area may reach more than 26 km, holding an estimated

in-place volume of some 1.4 billion barrels of oil equivalent.

Additional studies are being carried out to define this new

fields production development project.

The Xerelete discoverer well, the 1-EPB-1-RJS, drilled at a

water depth of 2,483 meters, reached sandy 17.5 API oil-

bearing reservoirs at a depth of 3,478 meters. This

accumulations productivity was confirmed via delimitation

well 3-RJS-648 (3-BRSA-481-RJS), where flows up to 2500

barrels of oil per day were registered. A new water depth

world record (2,460 m) was set at this well with the use of the

Submerged Submarine Centrifugal Pump.

Based on conclusive results from ESP well test, on

September 10th 2007, Petrobras announced to investors that it

has declared XERELETE field commercial to the National

Petroleum Agency (NPA).

This accumulation was discovered in an asset operated by

PETROBRAS, in partnership with TOTAL and DEVON.

Figure 2: Xerelete field location.

ESP WELL TESTESP WELL TESTESP WELL TESTESP WELL TEST ---- The The The The Integrated Appraisal ProcessIntegrated Appraisal ProcessIntegrated Appraisal ProcessIntegrated Appraisal Process

In order to determine the rock-fluid system characteristics,

evaluate the well potential and quantify the reserves, with

the consignment to be as most accurate as possible, and

based in the high probability that this well will not flow

naturally at 2460m water depth; it was required to perform a

pressure - production well testing with the use of an Artificial

Lift method.

Few alternatives were analyzed to perform the well testing.

The ESP (Electrical Submersible Pump) DST (Drill Stem

Test) system was concluded to be the best option that will

warranty the flow to the surface (as function of the reservoir

outflow), the data acquisition and then accomplish the whole

test objectives. Several analyses were evaluated to define

the pump set depth. The ESP string placed just above the

BOP required a contingency plan with Coil Tubing for diesel

injection. The choice was based on software PipeSim and

DesingPro simulation and results.

Normal preparation work for this type of offshore well would

take on average 2-3 months. This job was expedited in 2



weeks with full commitment and resources to ensure that

proper procedures and guidelines were followed as per

normal standard operating procedures which included

QHSE, ESP design, equipment selection and preparation,

transport, rig up and a contingency plan to re-start ESP after

static period.

MAIN CHALLENGES

Heavy and viscous oil

Low reservoir temperature, 160F @Datum

Water depth, 2460 m (8100ft)

Deep Water Off Shore Environment

Low temperature at sea bed riser, 4C

Heave/stability

Non-consolidated formations

Short notice given, 2-weeks campaign

The rig type was a semi submersible, SS-53, Noble Paul

Wolff (Figure 3).

Figure 3: SS-53 Platform

As mentioned, the downhole well testing, production lifting

and surface components used in heavy oil operations are

similar to those used in conventional oil production, with

some special modifications. The completion diagram,

including completions, oilphase, DST and ESP tools is

described in Figure 4.

Figure 4: Downhole String Diagram.



To optimize the testing phase, consideration was given to the

volume of drilling fluid lost to the formation while drilling, the

ESPs range of operation, and the flow rate desired while

testing.

For the ESP equipment design used in this exploratory well, it

was used the information from the Carapebus formation

which the lithology is Santoniano, a frail sandstone. The fluid

produced in the reservoir explored and tested has

overridden the specific gravity parameters and mainly high

viscosity were expected when flowing at sea depth due to

low temperature (4 degC), in such way the ESP equipment

was working under critical conditions of operation. Three

flows were performed at different downhole motor

frequencies and wellhead choke, lifting successfully oil

around 16 API and 40 cp at reservoir conditions, without any

downtime (see graphics).

Graphic 1: Clean-up and First Flow Period.

Graphic 2: Second Flow Period.

Graphic 3: Third Flow Period.

TECHNICAL RECCOMENDATIONS

Experience has shown that a mobile multiphase flowmeter is

fundamental equipment in these operations. The multiphase

meter used in conjunction with the artificial lift diagnostic

process enables ESP optimization during operations. High

frequency monitoring of the separation process in real-time:

oil, gas, water vessel level, densities, flow rates, oil content

in the water line, as well as the aperture of the oil, water and

gas line control valves when analyzed with the ESP

downhole sensor data helps to identify variations in flow

before issues occur.

ECONOMICAL IMPACTECONOMICAL IMPACTECONOMICAL IMPACTECONOMICAL IMPACT

For PETROBRAS and Partners:

This ESP-DST test helped Petrobras and its partners to

successfully test an exploratory well in ultra deep water.

This job allowed a conclusive evaluation in three flows; it

was conducted in 18 days without incidents nor downtime,

meeting all the objectives and client's expectations.

Current offshore development strategies incorporate an

extensive use of wells that provide access to sub-sea deep

or ultra-deep resources. Many concepts or technologies

have been discussed to improve the recovery and the

economics of these assets to produce them in the most

efficient manner. Today, projects have been integrated from

produce to float facilities, through subsea production

systems as a way for reducing the development and

operating costs.

Also, subsea boosting is seen as fundamental for providing

access to deepwater reserves. This concept is rapidly

growing and has gained Customer thanks letter to the proven



performance and reliability of similar artificial lift

applications.

For Schlumberger:

Every job brings approximately 1.5 MUSD of revenue for SLB.

More over, the successful implementation of a job like this

with tight schedule increases the chance to perform more

jobs in the near future. Petrobras drilling campaign for

exploratory wells is likely to include more of this type of well

tests in their planning for 2008.

For Artificial Lift Brazil:

In 2006, the Well Test Contract with Petrobras was

responsible for 27% of total annual revenue.

Year to date, the total receives with the contract is 4.3 million

USD, with 31% Net Income BT (with operation).

BUSINESSBUSINESSBUSINESSBUSINESS ANALYSISANALYSISANALYSISANALYSIS

MARKET SHARE

The Brazilian market for Heavy Oil and Deep Water Well Test

is recent and has been explored mainly for the major

company, Petrobras.

Since 2002, when Petrobras performed the first well test with

Schlumberger Artificial Lift, some of technologies have

changed, operational procedures have been improved and

people trained. The recognized growth and quality reached

after years gave to Schlumberger ALS an exclusivity

contract with Petrobras to test all Heavy Oil wells with

Electrical Submersible Pumps in Brazil.

Year to date were performed 21 Heavy Oil and Deep Water

well test, where 14 were carried out by Schlumberger and

one by Baker Centrilift, for a well test to Shell.

Graphic 4: Current Brazilian market for HO&DW well tests.

20022003

20042005

20062007

YTD

0

4

8

12

16

20

SLB ALS SLB ALS & PBRCompetitors SLB ALS & Others

MARKET OPPORTUNITIES

Auto Flow Sub Flow Check

Combined ESP and natural flow test

No well intervention

No control lines or hydraulic systems

Prevents pulling at wet string

Phoenix Saphire Select

More variables monitored

Pressure operational limit up to 10000 psi

Excellent long-term stability

Excellent accuracy

Highest temperature range

espWatcher

Real time Build-up and drawdown

Faster decision concerning flows time and

period

espWatcher & PhaseWatcher integration

allows

Matching well flow pressure and

surface flow rates

Confirming reservoir evaluation

CONCLUSIONSCONCLUSIONSCONCLUSIONSCONCLUSIONS

Petrobras and partners test objectives were

accomplished with success

Conclusive evaluation of Xerelete field with investors

announcement

Worldwide record for Exploratory Well Test with ESP in

ultra deep water

Quality Recognition by Petrobras HQ

Quality Recognition by SLB ALS LAM

Increase Service Revenue for AL

Opportunities identified for 3 NT5 (Auto Flow Sub,

Phoenix Downhole Sensor and espWatcher)

REFERENCEREFERENCEREFERENCEREFERENCESSSS

1. Resources to Reserves, OECD / IEA, 2005.

2. Heavy oil testing in deepwater wells - How can the

latest technologies and processes be best applied

for testing success?, www.heavyoilinfo.com, 2007.

3. New discovered in Xerelete Field, Petrobras

Investor Relations, 2007.

4. Artificial Lift NT5 Products, www.sail.slb.com, 2007.

first worldwide esp well test in ultra deep water- pbr

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