DEVEX 2012 9th European Production and Development Conference

Van Ghent Tri-lateral oil and gas development

An integrated challenge

Suzanne Castelein

2

Van Ghent Tri-lateral oil and gas development

Presentation Overview

1. History of the project

2. The first modelling efforts – gas focused

3. Studying the oil rim – can we make it work?!

4. An integrated challenge: the Tri-Lateral well

5. Results

3

Dana Petroleum Netherlands

Two producing platforms

Active exploration activity

Various non-operated production

High profit barrels

Base production

V Ghent

4

History of Van Ghent

Van Ghent Field discovered with Well P11-06

• Vertical exploration well; drilled early 2008

• Successful well; oil rim and gas cap found

• Triassic reservoir sands

• Shallow water (34 m)

Van Nes

Gas Discovery

Van Brakel

Gas Discovery

De Ruyter

Oil/Gas Production

Van Ghent

Gas/Oil Discovery

Nearest Facility: De Ruyter platform

• Oil platform

• Dana operated

• Extra production will extend

platform life

Medway Project born

• Tie-back of gas discoveries

• Adapting existing production

platform

Baron van GHENT

(1626 - 1672)

5

The first modelling efforts in 2008 – gas focused

Van Ghent Gas volume alone

justifies development

Part of De Ruyter Area Gas

Development,

Van Ghent largest gas in place of

the three discoveries

Attractive volumes, together with

Van Nes and Van Brakel

Van Ghent

1.4 BCM 12 MMstb

Gas/Oil Discovery

Van Nes

1.1 BCM

Gas Discovery

Van Brakel

0.4 BCM

Gas Discovery

De Ruyter

68 MMstb 1.1 BCM

Oil/Gas Production

Medway: Relative sizes GIIP and STOIIP

6

Studying the oil rim – how much is there anyway?

STOIIP calculations

•Static model needs detail on stratigraphy, rock properties

•Full petrophysical review, integrated for all 4 fields (De Ruyter, Van Ghent, Van Nes, Van Brakel)

• Implementation of sedimentological concepts Triassic Sandstones

7

Studying reservoir characteristics

Van Brakel Van Ghent

GR Neut/Den Por Perm

Upper

Lower

GR Neut/Den Por Perm

Van Ghent

average porosity 25%

average permeability 500 mD

8

Defining the oil in place

GR Neut/Den Sw Lithology Pay

9

The 3D Static Model

Top Reservoir Structure

Porosity model

Fluid contacts

10

Studying the oil rim – can we make it work?!

Gas cap development as basis

An 11.6 meter ‘thick’ oil rim,

can that be developed economically as upside

• PVT, extensive SCAL programme

• Three phase challenges

• Dynamic model gridding

• Many development concepts investigated

• Horizontal well needed to limit drawdown coning

• Depth of placement in thin oil rim

• Reservoir connection length

Dynamic grid

Stratigraphic grid

11

Well Planning – from modeling to ‘real’ well

Surface location west of shipping lane

Pilot hole to reconfirm fluid contacts and land horizontals

Maximum horizontal coverage in oil rim

Drainage point for the gas

STOIIP map STOIIP map

12

Van Ghent Gas Production

P11-6

Van Ghent Horizontal + Pilot_PWP_rev_D_01

1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400

1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400

-1880

-1840

-1800

-1760

-1720

-1680

-1640

-1600

-1880

-1840

-1800

-1760

-1720

-1680

-1640

-1600

0 100 200 300 400 500m

0

40

80m

Several alternatives considered

• Recompletion P11-06 (exploration well)

• Heel re-perforation of oil lateral

Choice: Tri-Lateral

• Drill third lateral into the gas cap

Earlier plan: From the north Final plan: from the south

GAS Lateral (S3)

Depth S1 = Depth S2

COMPLETION WITH

SCREENS & ICDS

GAS FLOW

OIL FLOW

FROM 2 Laterals

CO-MINGLED FLOW

OIL Lateral (S2)

OIL Lateral (S1)

Completion Concept

Summary of 3 years Modeling - Well placement and recovery

N1

N4 N6

N2

N5

N7

N3

S3 S4 S5 S6

Hydrocarbon distribution

Gas

Oil

Oil Recovery = Effectiveness to squeeze oil sponge

• Liquid off take

• Water Coning

• Gas Coning

• Aquifer Drive and Sweep

• Time !!!!

14

2011 Final Plan

“Maximum reservoir exposure, tri-lateral, intelligent, auto-gas lift, subsea well”

• Risk mitigation: coming from south, drill sweet spot first

• Pilot hole location close to landing point of horizontal oil laterals

Scale 1:1

Pilot hole

Gas lateral

Oil laterals

15

An integrated challenge: the Tri-Lateral well

We’ve done it before

•Analogue from De Ruyter producing oil laterals

•Principle works, same formation, same depth (~1700 m TVDss)

We’ll do it better

•Twice as long horizontals (2*2000 instead 2*1000 m)

•Half as thick oil rim (11.6 instead of 19.5 m)

3 years between discovery of Van Ghent Field and drilling Tri-Lateral development well

•Modelling work (static and dynamic) simultaneously with well planning

•All disciplines in-house;

– Geol & Geoph, Petro Ph, Res Eng, Pet Eng, Well Eng & Compl

•Constant iterations crucial to meet project deadlines

•Extensive peer reviews held to sense-check the work

•Early management buy-in

16

The REAL Tri-Lateral well

All four legs of the well are successfully drilled (total 8054 m!) and completed

•Pilot hole (2400 m AH)

•2 oil legs (drilled 2000 and 2254 m AH)

•1 gas leg (drilled 1400 m AH)

Well came in on prognosis

•Depth top reservoir

•Stratigraphy

•Pressure and producibility

Pilot hole

Gas lateral

Oil lateral

P11-06

17

Results

First Tri-Lateral in the Netherlands, now on production

The well performs according expectation;

•Oil rate at predicted level

•Both oil laterals seem to contribute

•Gas lateral still closed, as planned

Oil flare Gas flare

18

Questions?