❖ Effective Selection of Sand Control Techniques For New WellsIMPROVEMENT OF SAND CONTROL TECHNIQUES.

❖ Possible Controls To Wells Already Producing Sand In Order To Reduce Sand Production To Lowest Acceptable Level

OWI, WEST AFRICA7TH - 8TH MARCH 2018

KELECHI VICTORDRILLING & COMPLETION ENGINEERNIGERIAN AGIP EXPLORATION LTD

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1. Objectives

2. Fundamental Causes of Sand Production

3. Reasons For Sand Control

4. SandFace Sand Control/Lower Completion Methods

5. Sand Control Technique Selection Process

6. Possible Controls For Wells Already Producing Sand

OUTLINE

OBJECTIVES

▪ Uncover effective selection of sand control techniques for new wells

▪ Understand possible controls to wells already producing sand in order to reducesand production to lowest acceptable level

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FUNDAMENTAL CAUSES OF SAND PRODUCTION

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❖Destabilizing forces overcome formation strength

▪ Formation matrix fails

▪ If sand is mobile - sand transport (production) will occur

▪Sand production is a function of rock strength and/or fluid flow effects

Stage 1 - Failure Stage 2 - Transportation

FUNDAMENTAL CAUSES OF SAND PRODUCTION – Factor for Sand Production

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Formation or reservoir factors:

❖Rock mechanics

▪Overburden, intergranular friction, differential stresses

❖Formation lithology

▪Cementing material and degree of consolidation

▪Particle size, shape and distribution

❖Reservoir fluid characteristics

▪Viscosity, velocity and resultant drag forces (friction)

▪Changes in surface wetting

•Drag Forces

•Cementing•Capillary•Overburden

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FUNDAMENTAL CAUSES OF SAND PRODUCTION – Production Factors

❖Increased water cut – water coning or injection break-through

▪ reduces stability of perforation arch

▪ higher drag forces

Water break through can effect the performance of the formation cementing material

or change the flow characteristics which

destabilises the formationsand

FUNDAMENTAL CAUSES OF SAND PRODUCTION – Production Factors

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Pressure depletion, rock failure and reservoir compaction

Formation stable against overburden

Destabilized formation compacted by overburden

FUNDAMENTAL CAUSES OF SAND PRODUCTION

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❖Once the destabilizing forces overcome the formation strength, the rock will fail.

❖Sand production will follow if sand can be transported.

Fines migrate through matrix

Sand is the load bearing solids.

REASONS FOR SAND CONTROL

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❖Produced sand disposal

❖Formation stability

❖Equipment erosion

❖Impaired fluid flow and wellbore access

❖Realizing full well productivity

REASONS FOR SAND CONTROL – Sand Disposal

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❖Cumulative sand production

▪ plugs equipment or reduces efficiency

❖Production shut-down

▪ routine separator cleaning required

▪ high-cost activity

❖Sand clean-up required

▪ oil removed before disposal

REASONS FOR SAND CONTROL – Formation Stability

❖Failure may occur due to :

▪Non uniform lateral loading as rock is produced.

▪High axial compressive load due to slumping of the overlying casing-bearing formation.

REASONS FOR SAND CONTROL – Equipment Erosion

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❖Sand production can cause erosion in both surface and downhole

equipment such as :

Downhole Surface

Blast Joints Chokes

Gas lift Equipment Elbows / Tees

Pumps Metering Devices

Safety Valves Flow line

Circulating sleeves Flanges

Nipples Wellhead

Tubular Valves

REASONS FOR SAND CONTROL – Impaired Fluid Flow and Wellbore Access

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❖Sand loading or bridging

▪ Impaired productivity

▪Restriction to wellbore access

❖Implications

▪Well intervention required

▪ bailing or washing

❖Sand management required

▪ severity/frequency

▪ economics

SANDFACE SAND CONTROL/LOWER COMPLETION METHODS

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❖ Restrict production rate

❖ Perforating strategy

❖ In-situ sand consolidation

❖ Resin coated gravel placement

❖ Stand alone screens

❖ Expandable screen systems

❖ Gravel pack (cased or open hole)

❖ FRACPAC

SANDFACE SAND CONTROL – Restrictive Production Rate

❖If production must be constrained to avoid sanding, the

completion is generally considered a failure.

❖Restricting production rate may be appropriate:

Some weak formations have enough strength to produce

sand-free at low rates.

On sensitive formations where rock properties may change

during the production (i.e..., water production).

SANDFACE SAND CONTROL – Perforating Strategy

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❖General objectives include

▪Maximizing the stability of individual perforations

▪Avoiding collapse of structure between perforations

▪Optimum shot density and phasing

▪Oriented perforating guns

▪Deep penetrating charges

▪ Perforate interval with the strongest formation

✓selected from logs

SANDFACE SAND CONTROL – In Situ Consolidation

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❖Resin material is pumped into the formation

❖Furan Resin “glues” formation grain-grain into a consolidated structure

❖Compressive strength >1,000 psi with 60-75% retained permeability.

❖Injection of consolidation resins into the formation.

▪ sand grains bound with pore spaces left open

▪ rock matrix compressive strength improved

▪ efficient diversion critical

▪ detailed in “ScreenlessTechniques”

SANDFACE SAND CONTROL – Resin Coated Gravel

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❖Proppant ( Gravel ) is precoatedwith resin material.

❖Particles are mixed with viscous gel and pumped into the formation.

❖Particles are contacted grain-to-grain.

❖Temperature + H2O fuses the particles together into a consolidated permeable, drillable network.Main Water Shutoff system: e.gSandlock V

Resin

Formation

(Unconsolidated)

Gravel

LOWER COMPLETION METHODS – Stand Alone Screens (SAS) or Natural Sand Pack

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❖ Installation of a screen system

without gravel

▪ cased or open hole applications▪ premium screens are preferred

❖ Applicable mainly for sandstone

formations with:

▪ Good uniformity coefficient, i.e., well sorted sand grains

▪ Low percentage of fines

❖ Risks:

▪ Plugging of screens▪ Erosion due to production hot-spot

LOWER COMPLETION METHODS – Stand Alone Screens (SAS) or Natural Sand Pack

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Screens Expandable Screens

LOWER COMPLETION METHODS – Typical Gravel Pack Completion (IGP)

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❖ Consists of sized

particles placed in the

annular space between

an unconsolidated

formation and a

centralized screen.

❖ Open ( EGP) or cased

hole ( IGP).

Packer

Tubing

Blank Pipe

Sump Packer

Proppant

(gravel)

Casing

Seal Assembly

LOWER COMPLETION METHODS – Horizontal Open Hole Gravel Packing

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Two main placement techniques:

❖Water packing

▪ brine carrier, high rate, low concentration

▪ sustained circulation required during job

❖Alternate path

▪ viscous carrier, low rate, high concentration

▪ sustained circulation not required

LOWER COMPLETION METHODS – Frac-n-PACK

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❖ In FRACPAC, we place a fracture and a gravel pack in one step using a bottom hole assembly, that includes:

❖ The QUANTUM* Tool System with accessories, blank pipe and screens.

❖ High conductivity path for produced fluid which minimizes drags associated with draw-down pressure

❖ By-pass formation damage

❖ Restore formation stress

❖ Reduce matrix flow velocity

❖ Connect reservoir layers

❖ Stimulate the well

StimPAC

Gravel Pack

Damage radius

Fracture

Formation

SAND CONTROL TECHNIQUE SELECTION PROCESS

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❖ Selection for a new well is based on information from field, Exploration and laboratory activities as shown below

SAND CONTROL TECHNIQUE SELECTION PROCESS

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SAND CONTROL TECHNIQUE SELECTION PROCESS

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POSSIBLE CONTROLS FOR WELLS ALREADY PRODUCING SAND

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❖ Flow chart for already existing well that is producing sand

▪Dedicated well testing and data acquisition required

▪Laboratory testing of produced sand must be done to confirm the type of sand produced

POSSIBLE CONTROLS FOR WELLS ALREADY PRODUCING SAND

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THANKS

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