Part IV - Well productivity estimating methods

Inflow Control Valves

Inflow Control Valves can be classified according to the following attributes:

Number of positions they can take:

Two-point ICV, enable to take only two positions (“on/off”);

Multipoint ICV (6-11 positions), (Fig. on the left)

Infinite point ICV (Fig on the right)

Type of control system:

Hydraulic (for two-point and multipoint ICV)

Electric (for infinite-point ICV)

Combined (for all types)

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High Technology Wells.

Main manufacturers and geography of deployment

Main manufacturers of high technology assembly (SPE 106011, 2006):

WellDynamics (Haliburton’s division) ~50% of market

Baker Hughes and Schlumberger - 20-25% each

The rest is split between BJ Services, Weatherford and others

Main regions of use :

North Sea and Norwegian Continental Shelf;

GOM;

Shelves of Bruney and Malaisya;

Offshore / onshore fields on the Persian Gulf countries;

Shelf of Nigeria;

Shelf of Brasil

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Tasks that can be solved by means of «Smart Wells»

1.Optimal production from several reservoirs

2.Control of injection to several reservoirs

3.Drainage of several oil zones in separate reservoirs

4.Production from oil rims

5.Intrawell gas lift

6.Variable gas production

7.Inflow control from several boreholes of a multibranch well

8.Increase of sweep efficiency in a system of producing and injection wells

9.Etc.

+ combinations of the above tasks

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Production from oil rims

Inflow profile to (a) conventional HW and (b) High Technology Well

In (a) well inflow profile distributed unevenly because of pressure drop along the well. As a result, earlier water and gas breakthrough in the heel region. In case (b) inflow profile is equalized.

a)			Gas	b)			Gas
		Oil rim
						Oil rim

	Water		Water

Pressure drop

Pressure drop

Well length	Well length
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Intrawell gas lift

1.Gravel pack.

2.Pressure and temperature sensors on the outer side of production tubing;

3.Packers;

4.Pressure and temperature sensors on the inner side of production tubing;

5.ICV controlling gas rate to production tubing

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Energy of gas cap is used to lift the oil

Examples of application:

Troll (Norsk Hydro, North Sea) – optimization of production from the oil rim

Abqaiq (Saudi Aramco) – securing the well flowing with high watercut

Fram Vest (Norsk Hydro, North Sea) – managing high well head pressure for increased oil production

Norne (Statoil, North Sea) – securing the subsea well flowing as an alternative to ESP or conventional gas lift application

Egret (Shell, Bruney shelf) – same + managing high well head pressure for stable transport of oil from subsea asset to a stationary platform

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HTW: commingled production from 3 reservoirs, Na-Kika field, GOM

Vertical cross-section

Fourie field, Na-Kika project

Plots of cumulative oil production for commingled (red) and sequential (blue) production scenarios

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Alternating gas production

Layout is similar to that for intrawell gas lift. Used for securing increased gas production rates if required for a higher consumption. In this case deliverability of ICV to control production from the gas interval should be higher than required for the intrawell gas lift.

Oil production. Gas interval shut in

Gas production. Oil interval shut in

Examples of		Vestflanken (Norsk Hydro, North Sea)
application:		Brent Charlie (Shell, North Sea)

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Improving sweep efficiency in a system of injection and production wells

Displacement of oil by water in

heterogeneous reservoir by means Same + application of ICV of horizontal injector and producer

Producer

Producer

Stream

lines

Injector	Injector
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Example

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Problem setup

Oil viscosity μo=0,55 cp;

Water viscosity μw= 0,3 cp;

Bubble point pressure Psat=245 bar;

Solution GOR R =100 m3/m3

s

10,65 million m3

330 bar

352.5 bar

25,1 million m3

Prepared by Alexey Khrulenko, 2011