Subsea Boosting Offers Field Development Solutions E&P April 2017 Onesubsea

User Manual: Subsea Boosting Offers Field Development Solutions - E&P - April 2017 Resource Library

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APRIL 2017

Frontier Exploration

MPD/UBD

Production

Management

Rig & Drillship

Effi ciency

Regional Report:

MEXICO

MEXICO

EPMAG.COM

April 2017 | EPmag.com

Phillip Luce, OneSubsea, a Schlumberger company

When subsea boosting was implemented in 1994,

it opened a new frontier for offshore develop-

ments. In today’s tough environment the technology

has become more impactful than it was back then. The

industry of late has been looking to innovative technol-

ogies in an unprecedented manner to overcome low

oil-price woes. Introducing innovative methodology

associated with subsea boosting technology aligned with

project specifics is becoming even more relevant during

the recent industry downturn. The value of subsea

boosting technology is now being closely associated with

a fixed development concept that takes into account

various boosting methodologies including tiebacks, well

deferral and brownfield revitalization.

Production economics

Subsea boosting will improve field economics by reducing

backpressure on the reservoir, which will increase produc-

tion rates. By allowing the pump to reduce the backpres-

sure on the reservoir, an increase in well flow rates and total

recoverable reserves results and flow assurance improve-

ments such as increasing velocity in pipelines, temperature

increases and production stability also are achieved. Deep-

water and ultradeepwater Gulf of Mexico (GoM) operators

who are embracing this technology (which has been used

in other regions for some time) stand to gain much from

both the production and economic perspectives.

At higher oil prices more wells were being drilled, flow-

lines were being added and more subsea hardware was the

norm. Today the industry downturn has helped to highlight

different approaches to field developments such as tiebacks,

well deferral and brownfield revitalization.

The tieback option and use of a subsea pump is

attractive in terms of reducing overall field develop-

ment capital costs and improved recovery rates. In the

instance of day-one boosting, net present value can

be significantly increased by implementing a phased

drilling approach, allowing the operator to see the

benefits of the pump to maintain or increase the target

production on top of saving drilling costs. In the case of

brownfield revitalization, oil production from a mature

field can be renewed by using a pump to supplement

the amount of energy to drive the reservoir production.

Business case to accelerate production

This better understanding of economically viable

alternatives has led to customizing the methodology

associated with each application of subsea boosting. For

example, one GoM operator has seen enhanced pro-

duction and field life extension. Based on the natural

production curves, the required targets could not be

reached to make the project economical. However, by

implementing a subsea pump, this operator was able

to increase production to the target levels and extend

the production plateau, thus making the project viable.

Cumulative effects of increased recovery also were wit-

nessed in the later stages of well life (Figure 1).

In another field, an operator could reach production

targets; however, enhanced production was desired. By

including a subsea pump in the field architecture, the

early years provided an accelerated production wedge

that offered an immediate return on investment and a

greater return on capex, allowing the project to become

economically viable.

Subsea boosting offers eld

development solutions

The GoM stands to benefit from new wave of subsea boosting.

ENABLER

FIGURE 1. In a field where a target production was desired,

use of a subsea pump resulted in accelerated production and

extended plateau during the field’s early years, offering an

immediate return on investment and a greater return on capex.

(Source: Schlumberger)

Not economical

Economical with boosting

AS SEEN IN

APRIL 2017

Well deferral: sensible economics

Another GoM operator was able to get over the

FEED hurdle by applying a well deferral scenario

that allowed the company to increase production

while maintaining a better return on investment.

The operator had originally planned to drill multiple

wells. However, the operator was struggling to pass

the FEED stage. By deferring two wells and only drill-

ing three initial wells, the operator was able to use a

subsea pump to boost these three wells, increasing

production and in turn paying back costs incurred at

project startup (Figure 2).

Tieback vs. host facility

One operator, also in the GoM, found that taking a tie-

back-to-existing facility approach had significant savings

rather than taking the traditional approach to create a

local host for the development. While a local host was

considered in the early stage of the project, economics

were just not strong enough to support that concept. A

review was conducted of surrounding infrastructure that

identified multiple tieback opportunities. First under

consideration was a 32-km (20-mile) tieback. The effects

of adding subsea pumps allowed this concept to support

increased production over natural production while

adding higher arrival temperatures and optimizing flow-

line sizing. Second under consideration was to exam-

ine the effects of extending the tieback to 48 km (30

miles), which still showed promising economics through

boosted production. Considering the overall produc-

tion of the field, the 32-km boosted concept provided

the most economical solution, allowing the operator to

progress the concept where a local host was no longer

needed (Figure 3).

Brownfield revitalized

When a GoM operator’s reservoir was maturing and

reaching the end of its natural production, the oper-

ator decided to evaluate subsea boosting technology

as a concept to remove the overburden and constant

pressures being placed on the reservoir. Through the

implementation of subsea boosting, the operator was

able to revitalize the field and extend field life by many

years. This allowed further reduction in overall life-

of-field costs. Subsea pumps were able to reduce well-

head pressure while increasing total recoverables. The

subsea pump also was used to alleviate flow assurance

instabilities. Terrain slugging was present due to the

maturing natural production. By the pump increasing

velocities in the flowline, slugging concerns were elimi-

nated. An additional enhancement of pump operations

was the ability to restart flowing conditions from the

weak wells. Taking advantage of these multiple subsea

pump operational benefits, an additional 30 MMbbl

were recovered.

Continuing a legacy of innovation

Subsea boosting technology, when combined with a

well-planned and well-executed development design,

yields economically viable projects and delivers the

optimal solution for various well conditions and devel-

opment drivers. With a multitude of GoM wells possi-

ble to be tied back and many brownfields on the

decline, options abound for operators in the GoM to

leverage subsea boosting as a technology and economic

enabler. Under the current economic conditions sub-

sea boosting promises to become a concept that will

continue to challenge the industry to reevaluate proj-

ect development scenarios.

COVER STORY:

SUBSEA

DIFFERENCE BETWEEN NATURAL AND

BOOSTED PRODUCTION

FIGURE 2. By incorporating subsea boosting, a well deferral

scenario was implemented that allowed the operator to

increase production while maintaining a better return on

investment. (Source: Schlumberger)

FIGURE 3. Rather than create a local host for a GoM field

development, a 32-km boosted tieback provided the most

economical solution. (Source: Schlumberger)

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