COPYRIGHT. Sand Control Core. Introduction. This section will cover the following learning objectives:

Transcription

1 Learning Objectives Introduction This section will cover the following learning objectives: Identify the need for sand control Recognize the causes of sand movement Define what consolidated sand is, and what it is not 1

2 H T Oilfield Sand Production is a Worldwide Problem O PY R IG Why does sand production create such a problem? C Examples of Potential Sand Control Problems 2

3 Examples of Potential Sand Control Problems Examples of Potential Sand Control Problems Apply API 14E standards to limit allowable produced gas well rates to effectively minimize erosive conditions 3

4 Examples of Potential Sand Control Problems Production Rate Examples of Potential Sand Control Problems 4

5 Examples of Potential Sand Control Problems $ Sand Control Practices Completion and operations engineers carefully monitor formations prone to sand production Decisions are made early in a field development or redevelopment project regarding the need for sand control practices These practices include: Doing nothing and tolerating an expected very small or insignificant sand volume production Imposing rate restrictions to limit sand production potential Using complex gravel pack and frac pack mechanical well completions Using other well completion methods such as slotted or preperorated liners, screen mesh designs, expandable sand screens, resin consolidation techniques, proprietary mechanical sand control completions, and other approaches 5

6 Sand Control A Safety Issue Before being a productivity issue, it is a safety issue Thk: 2.9 mm Flow Direction Thk: 1.9 mm Thk: 1.6 mm Thk: 1.9 mm Thk = Wall thickness Tubing Blast Joint Failure from Sand Erosion * Note the degree of erosion / wall thickness thinning due to sand production. 6

7 Causes of Sand Production The formation components move when: The forces induced by the flow or other factors are stronger than the forces that hold the grain in place This can result from: Compaction squeeze Radial differential pressure Fluid inertia Fluid drag Acidizing Relative permeability effects Reduction of bonding strength Change in choke setting Other Spike Sand Production Waterflooding Sand Production Spike: Temporary likely a reaction to a change in well operations # of sand per bbl Changes Due to: Flowrate Drawdown Slight saturation Time or Volume Flowed 7

8 Catastrophic Failure T Catastrophic Failure H Temporary Condition Large scale saturation Depletion R IG # of sand per bbl Sand Production Failure: Major event which fills the wellbore and possibly surface facilities; requires a well workover O PY Time or Volume Flowed Consequences of Sand Production Sand production causes damage to facilities and resultant curtailment or production shut-down Surface separator filled with produced sand, requiring cleanout C 8

9 Which Reservoirs Produce Sand? Many ways of classifying sandstone strengths One method: Unconsolidated sand Very, very weakly consolidated sandstones Will produce sand at some point Consolidated sandstones O PY R IG Highly consolidated sandstone Normally no sand control problems H Weakly consolidated sandstones T Very weakly consolidated sandstones C Sand Classification Zero strength Dry sand Strength from Capillary forces Damp sand Varying sand strengths and their classifications from very, very weak, to very weak, to weak, to degrees of consolidation involve capillary pressure, cementing, sand compressive strength and related compaction for each sand sampled Source: Schlumberger 9

10 Potential Causes of Sand Movement Fluid saturation changes Surfactants in drilling fluids, completion fluids, etc. Acid stimulation treatments Solvents Reservoir fluid flowrate / velocity changes and increased drag forces Changes in the overburden stress, increased as fluids are withdrawn Additional phases causing relative permeability problems Shut-in and start-up changes which alter the sand packing arrangement near perforations Other Exercise Sand Production Two formations are under evaluation by a major production company. One is a Late Eocene sandstone (about 60 million years old) and the other a Permian sandstone (about 350 million years old). Which formation would likely have a greater chance of having sand production problems? Why? Late Eocene sandstone is much shallower and would have a greater chance of being more unconsolidated. 10

11 Summary It is mandatory that an asset team tasked with field development and operations consider a formation s lithological properties to assess the potential to both: a) Produce formation sand b) To plan accordingly to design the most effective approach to managing sand production problems This module addresses: The conditions surrounding sand production The approaches taken to choose the most effective remedial techniques applicable for a wide variety of cases The API 14E standard addressing erosional velocity limits The engineering procedures to design a modern gravel pack completion The various empirical design steps for understanding effective sand control techniques Learning Objectives This section has covered the following learning objectives: Identify the need for sand control Recognize the causes of sand movement Define what consolidated sand is, and what it is not 11

12 Learning Objectives Sand Control Completion Options and Design This section will cover the following learning objectives: Identify both non-mechanical and mechanical methods of sand control Recognize that rate restriction is a valid practice to manage sand production Recognize that minor sand volume produced may be tolerated 12

13 Sand Control Methods Various Options No Direct Mechanical Control Sand Control Methods Various Options No Direct Mechanical Control Mechanical Methods Living with / dealing with limited sand production Surface sand separation Rate reduction Cavity formation, wormhole formation Selective completion practices Wellstream desanders High-density and/or phase-oriented perforating Small volume of sand Safe operation with no threats to erosion Wellhead desanders Difficult to sell to management Avoid areas that produce high sand volumes Wellbore trajectory designs horizontal, laterals, etc. Access only sections free of sand problems 13

14 Sand Control Live With It RESERVOIR PRESSURE + SAND FREE FIELD PROVEN LIMIT DRAWDOWN + SAND PRODUCTION 150 psi (134 kpa) drawdown may induce sand production on unconsolidated turbiditic sandstones No Control / Cavity Formation / Rate Restriction Will sand move continuously? Is it tolerable? Will sand stop moving, after cavity formation, when velocity drops below threshold necessary to tear sand loose from formation? 14

15 No Sand Control Do nothing and let sand be produced Not unrealistic as an approach Risks Wellbore fill accumulation Sand disposal Subsidence Casing collapse or damage Surface erosion or blockages High well maintenance High facilities maintenance including shut down Cavity Formation Enlarging the wellbore, whether by perforating (tunnel extension), underreaming, wormhole formation or cavity creation, increases the area of contact with the formation and decreases the flowing fluid velocity at any set flowrate Original hole Becomes 15

16 No Sand Control May require no more than: Periodically removing a small amount of produced sand from surface facilities and bailing the well; and, Regularly pigging surface flowlines The overall cost of doing nothing may be small Minimal sand production may have little negative effect upon operations No Sand Control But, Limit Velocity Slow down fluid movement rate at the sand face Larger / more perforations Larger wellbore Reduce the rate Underream Cavity completion In this case, note minimal sand in separator 16

17 Sand Production Strategy First Reduce the Frictional Forces (Flow Rate per Unit Area) 1 Provide Clean Perforations 2 3 Open Increased Section Increase the number and/or size of the perforations Consider horizontal well completion Create a Conductive Path into Formation Gravel pack the well Frac pack the well Mechanical Methods of Sand Control Chemical Consolidation Resin-Coated Sand Slotted Liners or Screens without a gravel pack Open Hole or Cased Hole (not recommended) Slotted Liners or Screens with a gravel pack Open Hole or Cased Hole Frac packing or Fracturing Expandable Screens Vent Screens 17

18 O PY R IG H T Perforating May De-Stabilize the Formation C Perforating Creates Perforation Tunnel Damage 18

19 Perforating Creates Perforation Tunnel Damage Exercise Sand Production Two well completion perforating designs are under evaluation by a major production company. Both are weakly consolidated sands. One is being completed using 4 shots per foot (13 shots per meter) of zone thickness Inches Entrance Hole Dia CFE 0.73 TTP 4.48 TCP 3.36 ECP The other at 12 shots per foot (39 shots per meter) (23.1 mm) (18.5 mm) (113.8 mm) (85.3 mm) 2.47 (62.7 mm) Which completion would likely have a greater chance of having sand production problems? Why? Careful additional study is necessary to size diameter and determine pressure drop through each perforation. Well drawdown would need to be carefully managed to restrict rate to constrain tendency of sand to flow. 19

20 Resin Consolidation Creates stronger matrix by cementing grains together with synthetic plastics / chemicals Leaves wellbore open Hard to evenly apply Length of effective life questioning Industry results with resins have been mixed and the jobs may be short-lived Many new products available Resin-Coated Gravel The gravel is placed in the perforations and also fills the wellbore Gravel is pre-coated with resin After allowing the resin to set, drill out the wellbore, leaving the perforations filled with the consolidated gravel Also used for other purposes, such as screenless frac packs 20

21 Mechanical Sand Control Methods Screen Alone or Screen with Gravel Basic Problem Control sand without reducing productivity Design Parameters Optimum gravel-sand size ratio Optimum slot width to retain gravel or sand Effective placement technique Learning Objectives This section has covered the following learning objectives: Identify both non-mechanical and mechanical methods of sand control Recognize that rate restriction is a valid practice to manage sand production Recognize that minor sand volume produced may be tolerated 21

22 Learning Objectives Non-Gravel Pack Completions, Options, and Design Alternatives This section will cover the following learning objectives: Identify various screen types for sand control Outline aspects of pre-packed screens for sand control 22

23 Wire-Wrapped Screen Consists of base pipe with drilled holes and wire-wrapped screen jacket Jacket is welded or mechanically attached to base pipe Rod-based screen without inner pipe is also available C O PY R IG H T The gauge of the screens is sized based on the formation sand size distribution Views of Sand Screen and Mesh Construction 23

24 Woven Wrap Mesh Mesh Ported base pipe Support screen Premium Screen Base Pipe Bakerweld Inner Jacket Vector Weave Membrane Vector Shroud 24

25 Pre-Packed Screen Note resin-coated sand between outer and inner wraps This type of screen offers improved abrasion control This type of screen plugs easily Pre-Packed Screen 25

26 Examples Non-Gravel Pack Horizontal Well Completions Open Hole With Slotted Liner Open Hole With Screen or Prepacked Screen Slotted liners and screens in a non-gravel pack are FILTRATION DEVICES Except For Expandable Screens 26

27 Learning Objectives This section has covered the following learning objectives: Identify various screen types for sand control Outline aspects of pre-packed screens for sand control 27

28 Learning Objectives Gravel Pack Completions, Options, and Design Alternatives This section will cover the following learning objectives: Describe the principles of sand control screen and gravel completions Identify the three steps comprising a gravel pack completion design Describe various fluid options for pumping gravel slurry into a gravel pack completion Outline the function of a gravel pack crossover tool Outline the function of a gravel pack shunt tube 28

29 Sand Control Principles: 3 Ways Bridging: Gravel Pack O PY R IG H Filtration: Stand-Alone Screen T Consolidation: Resin Sand Control Principles Gravel Pack Perforation Formation Sand C Screen Internal gravel pack recommended thickness of pack or pre-pack is 0.75 in. to 1.25 in. (19 mm to 31.8 mm) Casing Cement Perforation Tunnel 29

30 Gravel Pack Design Principles Gravel Pack Design Principle #1 Establish a highly permeable pathway between formation and wellbore that formation sand cannot penetrate Cased Hole vs. Open Hole Gravel Packs 1 2 Cased Hole Open Hole Gravel retains the formation sand in place Screen holds the gravel in place Gravel is placed between screen and casing, and inside perforations Gravel is placed between the screen and the formation Gravel Pack Design Principle #2 The trend is toward more open hole gravel packs being placed in horizontal wells 30

31 Gravel Pack Design Principles Gravel Pack Completion Sand Control O PY Bridging occurs at this interface R IG H T Works as a two-part retainer: Step 1: Gravel is sized to retain formation sand Step 2: Screen sized to retain gravel in place Gravel Pack Design Principles Importance of Good Bridging in a Gravel Pack Design POOR BRIDGING Formation Sand is Restrained By Gravel Pack Gravel in a Good Design Formation Sand Invades Gravel Pack C GOOD BRIDGING 31

32 Gravel Pack Design Principles 3 Steps 1 Obtain a good description of the formation sand grain size distribution 2 3 Select gravel size based on the formation sand grain size distribution 50% cumulative grain size x 6 for gravel pack 50% cumulative grain size x 8 for frac pack Select screen based on smallest gravel range 50% to 75% of smallest gravel range size Formation Sampling for Sieve Analysis Conventional Cores Sidewall Cores Produced Samples Bailed Samples Avoid Composite Samples, whenever possible 32

33 Conducting a Sieve Analysis in the Lab Conducting a Sieve Analysis in the Lab Core sample is frozen and then thawed During thaw, it breaks up into smaller components Sample is placed on the top tray Screens of different sizes filter sand formation sample into a range of different sizes 33

34 O PY R IG H T Conducting a Sieve Analysis in the Lab C Conducting a Sieve Analysis in the Lab 34

35 Conducting a Sieve Analysis in the Lab The following series of slides illustrate gravel pack design O PY R IG H T Sieve analysis results measure weight percent sample retained on each sieve size screen opening C 1. Determine Gravel Size for Gravel Pack 35

36 2. Determine Range of Gravel Size Using Median mesh inch mm microns mesh inch mm microns Gravel Pack Choose 20/40 Frac Pack Choose 16/30 2. Max/Min Mesh Size For Gravel Pack Example: 20/40 Gravel Pack choose 20/40 based upon Uniformity Coefficient Median Gravel size for gravel pack example: 570 microns (0.57 mm) [95 x 6] Median gravel size for gravel pack example: 570 microns (0.57 mm) 36

37 2. Determine Range of Gravel Size Using Median Blend gravel size range as follows: Gravel sizing specifications are per ASTM E-11 and API RP 58 Gravel size distribution is a bell shaped curve by weight A 20/40 distribution mean % retained on sieves is approximately Sieve Size % 20 mesh mesh mesh mesh mesh mesh 0.8 Max / Min Range Gravel sizing is a function of the Uniformity Coefficient of the grain size distribution plot Also, < 2% undersized gravel is allowed (i.e., gravel may not be smaller than 40 mesh for 20/40 gravel) 3. Determine Screen Slot Cut Spec as 75% of Min Gravel Size Therefore: screen slot spec is 75% x in. (0.42 mm) = in. (0.32 mm) Illustrates size conversion Minimum Gravel Size Range (D 98 ) Gravel Pack choose 20/40 Frac Pack choose 16/30 mesh inch mm microns Median Gravel size for gravel pack example: 570 microns (0.57 mm) 37

38 Sieve Analysis Indicates Whether Formation has Uniform or Non-Uniform Grain Size Distribution Poorly Sorted Sand Well Sorted Sand Non-uniform Uniform (2.54 mm) (.254 mm) (.0254 mm) ( mm) Selecting Gravel Based Upon Sand Grain Size Uniformity Coefficient Sorting Coefficient Saucier d C u = d d C s = d D 6 = d Lower case d designates formation sand median diameter Upper case D is the selected gravel median diameter Gravel Formation sand Definitions to Assist Sand Control Design (SPE 37437) 38

39 Uniformity Coefficient Cu = d40 / d90 Cu = Uniformity Coefficient d40 = Grain Diameter at 40% Cumulative Weight d90 = Grain Diameter at 90% Cumulative Weight = Uniform Sand Distribution if 3 < Cu < 7 = Non-Uniform Sand Distribution if Cu > 7 = Highly Non-Uniform Sand Dist. H T if Cu < 3 R IG Sorting Coefficient is defined as Cs = d10 / d PetroSkills, LLC. All rights reserved. O PY 15 Various Grain Size Distribution Design Points Design Point = d90 C Design Point = d70 Design Point = d50 x6 Design Point = d40 Design Point = d10 (2.54 mm) (0.254 mm) ( mm) ( mm) 16 39

40 Design Point Selection for Gravel Pack Coberly and Wagner D10 10(d10) Saucier Method: The most common gravel pack design method Saucier D50 6(d50) Stein D85 4(d15) Schwartz D10 6(d10) for Cu < 5 D40 6(d40) for 5 < Cu < 10 H T D70 6(d70) for Cu > O PY R IG Lower case d designates formation sand median diameter Upper case D is the selected gravel median diameter C Gravel pack permeability ratio (Eff. vs Initial) Gravel to Sand Size Ratio (Saucier Method) Gravel sand size ratio (D50 Gravel vs D50 Formation) 40

41 Another Example: Grain Size Distribution Sieve Analysis Sieve Size Opening inches (mm).08 (1.52) (1.02) (0.51) (0.25) (0.203) (0.152) (0.102) (0.051) (0.025) R IG H T (2.54) (2.03) O PY U.S. Sieve Number Other Examples: Grain Size Distribution Sieve Analyses C U.S. Sieve Number Bailed Sample Core Barrel Sample Produced Sample (2.54 mm) (0.254 mm) ( mm) 41

42 Grain Size Comparison Analyses at Various Depths Same Well Grain Diameter US Mesh Size Grain Diameter (mm) Summary Review: Gravel Pack Design 3 Steps Obtain a good description of the formation sand grain size distribution Select gravel size based on the formation sand grain size distribution 50% cumulative grain size x 6 for gravel pack 50% cumulative grain size x 8 for frac pack Select screen based on smallest gravel range Design screen opening as: 75% of the diameter of the smallest gravel range size This size retains gravel in place behind screen 42

43 Gravel Pack Rules of Thumb Gravel to Sand Size Ratio Use a gravel size as large as possible; the sand must be retained at the outer edge of the pack The size of the gravel is usually 6 times the size of the formation sand at D 50 or D 40 (many other sizing techniques have been reported in the literature) For frac packs, multiply the median by 8 instead of 6 Pay more attention to smaller sand grain sizes with: Non-uniform sands Higher flow velocity Fluctuating flow rates High gas oil ratios Other Relevant Reservoir Criteria How Does Degree of Sorting Affect Gravel Sizing? Again Sorting Coefficient Defined as C s = d 10 / d 95 May Require Smaller Gravel Size if Highly Non-Uniform Fines % of particles smaller than 44 μm ( in.) 2010 PetroSkills, LLC. All rights reserved

44 Gravel Placement Fluid How is the gravel actually placed in the well? Gravel can be placed with brines or polymer fluids Super-clean fluid essential (especially for brines) No solids Most open hole pack failures result from surface solids (dirty fluid / brine / polymer tanks) Properly hydrate the polymer fluid Shear properly; permit no fisheyes Problems Viscosity and fluid loss control Density Key is achieving a tight pack Polymers as Carrying Fluid Three different polymer concentrations providing a wide range of viscosities 44

45 Polymer (HEC) Mixing Procedure (per bbl fluid) Use fresh water or 2-5% KCl or NH 4 Cl in water Lower the ph to 3-5 with citric acid [ lbs ( kg)] Disperse lbs ( kg) polymer in agitated tank Raise ph to 6-8 with caustic or soda ash Mix at high shear rate, but avoid over-shearing Monitor viscosity with Brookfield viscometer And run sand suspension test Monitor filterability 1 quart (946 cm 3 ) in 1-2 minutes Filter to remove any unhydrated solids Pre-hydrated polymers are also available Well Site Gravel Pack Pre-Job Preparation Onsite Gravel Pack Operations 45

46 O PY R IG H T Polymer (HEC) Carrier Fluid Being Mixed at the Well Site Prior to Job Gravel Pack Pumping Equipment Baker Hughes Sand Control Skid Mounted Frac Pack and Gravel Pack Pumping Equipment Package C Large volume operations Horizontal well applications Modular for offshore or onshore jobs Superior Energy Services Sand Control Barge Mounted Gravel Pack Pumping Equipment Package Rated for inland waters Pumps: 2 x 2000 hydraulic HP / 1 x 600 HP Sand storage / mixing tanks / sand screw feeder Wet chemical storage / delivery Related sand control support equipment systems 46

47 Stimulation Vessel Equipment Schematic The layout of the stimulation equipment on vessels and platforms for offshore frac pack and gravel-pack treatments is critical. On vessels especially, horizontal and vertical weight distribution affects the center of gravity. Equipment placement on platforms is crucial for personnel safety and efficient working conditions. Platform Rig Up 3 ½ in IF tubing with full-opening TTW valve Rig manifold to casing Electronic Pressure Transducers Flow Meter Radioactive Densometer Check Valve High-Pressure Discharge Line to Tubing Rig Pump High-Pressure Discharge Line to Offshore Vessel Blender bypass High-Pressure Regulating Pop-Off Valve High-Pressure Discharge Line to annulus Halliburton Lo Torc Valve Crew s Quarters and Wheelhouse Observation Deck and Control Room Downhole Pumps High Pressure Downhole Pumps High Pressure Downhole Pumps High Pressure Downhole Pumps High Pressure Downhole Pumps High Pressure Downhole Pumps High Pressure Downhole Pumps High Pressure Downhole Pumps High Pressure Proportioning Blender Gel feed line from below dock storage Gel feed line from below dock storage High-Pressure Regulating Pop-Off Valve Downhole Pump Suction and Discharge Manifolding Sand Tank Offshore Stimulation Vessel Hydraulic Quick Disconnect High-Pressure Discharge Line to Platform 47

48 Gravel Pack Equipment Packer Cased Hole Note that gravel also fills perfs Crossover open Gravel Packing Position.. Port Collar, Open Wash Pipe (Tail Pipe) Wire wrapped screen Gravel Multi-Function Gravel Pack Packer Crossover Tool Packer shifted to crossover position Carrier fluid and gravel are pumped down tubing and through tool to be placed in the screen / perforated casing annulus at perforations By job end, packer is shifted back to producing position 48

49 Horizontal Well Gravel Pack Completions Horizontal well pack gravel pack completions are quite common Certain mechanical methods should be used for an extended length horizontal gravel pack Horizontal wells allow significantly more reservoir access compared to vertical wells More access results in significantly higher well productivity Sand production is normally decreased because of lower fluid flux rates However, sand control if often required in horizontal wells Horizontal Well Gravel Packing Long horizontal wells can be successfully gravel packed using: Brine carrier fluids Gel carrier fluids (with alternate path technology) In cased hole mode In open hole mode Frac packs can also be successfully placed Expandable Sand Screens (ESS) have been used to control sand production Stand-Alone Screens (SAS) can be used (no gravel pack) but only in uniform sands 49

50 Gravel Placement in Horizontal Wells with Brine T Can completion and tight packing of the whole section be achieved in long extended length holes? O PY R IG H With proper design and equipment, the answer is Yes. Alternate Path Shunt Tube Configuration Shunt Tube Tool C Alternate slurry path Ports every 3 ft (0.9 m) gk14.ppt 50

51 Halliburton PetroGuard Shunt Tube System Use of a shunt tube in a gravel pack completion is referred to as alternate path technology to mitigate incomplete annulus gravel packing Two transport shunt tubes deliver slurry along the well and shunt tube path Two packing shunt tubes are separately connected from tubing joint to tubing joint R IG Gravel Exit Port H T Along the shunt tubes are exit ports for fluid slurry to leave the shunt tubes Transport Shunt Tubes O PY Packing Shunt Tubes Horizontal Well and Multi-Zone Gravel Pack Gravel Pack Equipment Tool String C Alternate path technologies allow gravel packing of horizontal wells using gel carrier fluids Zonal packing is also aided by shunt tubes from: Schlumberger 51

52 Sources of Gravel Packing Problems Formation sand mixed with shale layers Insufficiently packed perforations plugged by formation particles Damage from drilling fluid invasion Gravel crushed or mixed with formation sand Dirty gravel placement fluids Dirty brine(1) Improper gravel size Solids Invasion Solids Invasion Filtrate invasion (1) H T Improper perforation packing Crushed zone O PY R IG Case Study: An engineer s first gravel pack with complete responsibility for the job resulted in a total failure requiring pulling all G.P. equipment out of the hole, a cleaning out of the well, and the re-running of the entire completion. The failure was due to dirty tanks (even though a rigorous Clean Tanks spec was included in the gravel pack completion program) which picked up huge amounts of trash. The rig tried to pump it all downhole. This has not happened to the engineer ever since. All tanks are inspected!! Importance of Clean Tubulars and GP Equipment Clean tubing before setting packer (pickle tubing) C Acid Solvent Apply pipe dope moderately on pin only Check that equipment is free of rust, mill scale, acidizing and cementing materials Check that gravel pack completion equipment is not painted Check that fluids storage containment is thoroughly cleaned before mixing completion fluids 52

53 API RP 58 Gravel Quality Specifications Sieve analysis Less than 0.1% oversized and less than 2% undersized Sphericity and Roundness Average sphericity and roundness of 0.6 Acid solubility Less than 1% soluble in 12/3 HCl-HF mud acid Silt and Clay Content Turbidity NTU reading lower than 250 Crush resistance Less than 2% fines created by 2,000 psi (13,790 kpa) confining stress Gravel Pack Quality Control 53

54 Learning Objectives This section has covered the following learning objectives: Describe the principles of sand control screen and gravel completions Identify the three steps comprising a gravel pack completion design Describe various fluid options for pumping gravel slurry into a gravel pack completion Outline the function of a gravel pack crossover tool Outline the function of a gravel pack shunt tube 54

55 Learning Objectives Frac Pack for Sand Control This section will cover the following learning objectives: Describe the function of a frac pack completion Outline the frac pack completion well performance results 55

56 Frac Pack Completions Fracture completion and gravel pack completion combined Gravel / proppant pumped to fill fracture created Completion properties are: O PY R IG Enhanced rate and sand protection control H Gravel pack screen completion equipment in place T Highest end completion that can be designed allowing for both fracture productivity and protection against sand production as a gravel pack Frac Pack Sand Control with Well Stimulation C Conventional cased hole gravel packs often result in low well productivity, i.e., a high skin. A technique was developed to place short, wide fractures in cased holes, followed by a gravel pack in the annular space. Typical frac wing lengths are from ft (9 46 m). Typical fracture widths at the wellbore are 2-3 in (51-76 mm). 56

57 Frac Pack for Sand Control Top view of a well with a frac pack placed through the damaged zone Well drainage radius Wellbore damaged zone Frac pack half length Frac Pack Results Fracture has proppant with designed conductivity Typical skin value for fracpacked well: -2 to -3 Frac packs often result in 3 to 5 times more production compared to a conventional cased hole gravel pack Longevity / gravel pack well life often very good Fines migration is often completely eliminated 57

58 Frac Pack of Horizontal Wells Many operators are placing frac packs in highly deviated and horizontal wells Multiple frac packs may be placed in horizontal wells With multiple frac packs, well productivities are very high Screenless Frac Pack Wells can also be fracpacked without screens Usually resin-coated proppant will be used to hold the proppant inside the fracture (to prevent proppant flowback) Alternatively, resin can be pumped into the proppant at the end of the job Some early failures have occurred with screenless frac packs, while other operators have had good successes One major advantage is that the wellbore is left fully open for a larger flowpath Not as common as standard frac pack completions 58

59 Learning Objectives This section has covered the following learning objectives: Describe the function of a frac pack completion Outline frac pack completion well performance results 59

60 Learning Objectives Expandable Sand Screens This section will cover the following learning objectives: Outline the function of an expandable sand screen completion Identify the components of an expandable screen and possible benefits resulting from the use of expandables 60

61 ESS Expandable Sand Screens ESS joint and roller type expanding tool An ESS joint consists of: A slotted steel tube with overlapping layers of Petroweave filter membrane attached An outer layer of pre-slotted steel plate which holds and shields the membrane Connections function well after recent design improvements From: Weatherford 61

62 ESS Expandable Sand Screens Remedial Sand Control capability reduced workover costs Optimized O.D. / I.D. ratios maximized flow conduit, minimized well costs Reduced erosion potential Reduced P optimized productivity Borehole stabilization Sand Control for slimhole / slender wells Learning Objectives Example shown: 6" (15 cm) O.D. Pre-expanded 8-½" (21.6 cm) O.D. Post Expansion This section has covered the following learning objectives: Outline the function of an expandable sand screen completion Identify the components of an expandable screen and possible benefits resulting from the use of expandables From: Weatherford 62

63 PetroAcademy TM Production Operations Production Principles Core Well Performance and Nodal Analysis Fundamentals Onshore Conventional Well Completion Core Onshore Unconventional Well Completion Core Primary and Remedial Cementing Core Perforating Core Rod, PCP, Jet Pump and Plunger Lift Core Reciprocating Rod Pump Fundamentals Gas Lift and ESP Pump Core Gas Lift Fundamentals ESP Fundamentals Formation Damage and Matrix Stimulation Core Formation Damage and Matrix Acidizing Fundamentals Flow Assurance and Production Chemistry Core Sand Control Fundamentals Hydraulic Fracturing Core Production Problem Diagnosis Core Production Logging Core Production Logging Fundamentals 63