Solids Control Manual for Drilling Personnel

Figures 1-1 1-2

SwiGel' Area Resulting From Disintegration Swiaee Area From Successive Cube DivisioJ1.

2-1

Summary of Solids Control Equipment

3-1 3-2 3-3

Derrick Flo-Line Cleaner 2000, 3-Pane! Shale Shaker Motion Shale Shaker Techn%gy & Deck COilfigumfiolls

4-1 4-2 4-3 4-4 4-5 4-6 4-7

Plain Square Weave Rectangular Opening Patented Anti-Blindhrg Derrick Sandwich Screens Derrick Pyramid Screen Positiolls of Solids Oil PWP and PMp.screens Horseslwe Effect Original PMD and Modified Pal/em

5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9

Gas Bubble Action in Drilling Fluid Gas Bubble Location & Breaking Action Proper Design of Ml'ld-9a,~:'Separator I Atmospheric Degasser Horizontal Tank Vacuum Degasser Baffle Plates of Hori;.o11lal Tallk VaCiillill Degasser Vertical Tank Vacuum Degasser The Derrick Vacul/m Degasser Flow Diagram for Vacuum Degasser - Uses a Stacked, Corrugated Leaf Design 'Which Alloll's Superior Gas/Liquid Seperation, and Eliminates Remixing and Inefficient Cye/onic Resepel'Cltiolls

6-1

A Typical Balanced Design Hydrocyc1ol1e Operating Properly in . "Spray" Type Undo.flo1\' Solids Discharge A T)7)ial Balanced-Design Hydrocyc1olle that is Ol1.crloaded lI'ilh Solids and "Roping" Hydrocyclonc Unde/,f/ow Adjustnieflfs with Clear :Water Feeding Plugging in Balallced Design Hydrocycloncs Hydrocyclonc 'with Ullde,pow Opening Plugged Suction Screens to Protect Desilters Hydrocyclone Feed Header Problems

6-2

(

6-3 6-4 6-5 6-6 6-7

Figures. continued 6-8 6-9 6-10 7-1 7-2 7-3 7-4

7-5 7-6 7-7 7-8

8-1

Header Problem - SllfIp Discharge Caused by Long Siphon Leg OVCJ,f/OlF Header Problellls Wear Patterns in Hydrocyc/ones Derrick Mud Cleaner Mechanical Solids Control of Weighted Drilling Mud Typical Barite Size Distribution.for Commercially Available Barite Sample Distribution of Drilled Solids in Mud After Passing Through all 80 Mesh Screen Solids Removed by A1ud Cleaner Mud with High % (if Ultra-Fine Solids Should be Centrifuged Bentonite Size Distribution Superimposed Over the Distribution Presented in 200 Mesh Screen Locaf;rJIl of Mud Cleaner OVClf/OW

8-8a-c 8-9a-h 8-10

How Centrifugal Pumps Produce Pressure - Relationship Between Vertical Height (Pressure Head) and Impeller Tip Velocity Work liS. Shut-in Friction Total Dynamic Headior Centr(fugal Pump Centrtfllga/ Pump Cavitation Rig Up Problem - Close Suction Ell Settling of Solids in Pipe Hard Bed Fo1'inatioil - Velocities Above 300ft.l111il1. Will Prevent Settling Friction Loss in Feel o.fHead Pump Curves for Water, Derrick Centrifugal Pumps Pump & Line Problem for Classroom

9-1 9-2 9-3 9-4

Settling o.f Spheres ill Flllids, Stoke's Lall' Settling (~f Irregularly Shaped Particles hi Fluids, Stokes Law Centr(fuge Operafioll Centrifuge Bowll)'pes

10-1

Pro.file View o.f Derrick Hi "G" Dlyer ·with 10 bb/ Sump

11-1 11-2 11-3

LayOllt for Dual Centr(fuge System with Weighted Mud Layoutfor Singe-Stage Centr(fuge System with Weighted Mud Layol/tfor Sil/gle-Stage Celltrigllge Syste11lwitth Unweighed Mud

12-1

An Alternative Method to Detennine Removal Efficiency

8-2 8-3 8-4 8-5 8-6 8-7

Tables 1-1

1-2 1-3 1-4 1-5

Solids Diintegratioll - A Problcm Can Arise WifhOlI{{lI1/l1crease ill Solids Con/ent Micron Si;.e o.fComnuJ/1 Materials API Designationsfor Micron Si;.c Range,'\ Required Force for Stuck Pipe MOl'('menf

1~6 1-7

Solid COlllcllt in Variolls Drilling Fluids Effect qf Chemicals 011 Dispersion of Compacted Miocelle Shale Effects of Common Contaminants on Drilling Fluids

2-1 2-2 2-3

Target Drilled Solids Concentration Optimulll Hydrocyclone Operation Operating Range of CClItr(fuges

4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9

Derrick Screen Part Number Composition Speq/ications, Derrick PMD DX Series Spcq'(ications, Derrick PMD HP Series Spec({icatiol1s, Derrick PWP DX Series Spec({icatiol1S, Derrick PWP HP Series Spec(j1cafiolls, Derrick SWG-DX Screens Screen Comparison Chart Areas af PWP and PMD Screens Increases ;n Screen Area for Various Screen Co~nbiJ1atioJ1s Comparative Screen PeJi0I711(fnCe Test Results from Hardin Coullty, Texas Operatiolls

4-10 4-11

i' .

8-1 8-2 8-3 8-4

Example of POllnds Tra/1,~ferrancefor Water I's. Mud Example of Pump Head and System Loss Friction Loss in Fitting - API Units In Approximate Equivalent Feet of Straight Pipe Dynamic Head and Pump Selection, APl Units

10-4

Mud Cleaner Ecollomic Data for FOllr lVells Average Mud Loss by Screen Si;.e Past McAllen Wells Average Cost Well Cost Using Hi "G" Dryer and Cajun Construction

12-1

Solids Analysis Formulas

10-1 10-2

10-3

Formulas I-I 1-2 1-3 1-4 \-5 2-1

Filter Cake Thickness Equation

Required ForIo}" Stuck Pipe Movement Reynolds Number

Drilling Rate in Relatioll10 Reynolds Number Drilling Rate ill Relation to Plastic Viscosity

2-3

Dilution Rate Cost Sewings Calculation Feel of Head

3-1

"g" Faclor

5-1

Boyles Lall' - Pressllre- Volllme Relationship for Gasses

6-1

NOll-Pressured FlolV Through a Pipe

7-\ a 7-1 b

Slliny-Del1sity, Head-Pressure Relationship Feet afHead Requiredfor Proper Hydrocycionc Operatio1l

8-la 8-lb 8-2 8-3

Pressure Head

2-2

9-1 9-2 9-3 9-4

Pressure Head & Equiva/e11l Head Velocity

Centr(fifgal Pump Pressure Head "g" Force for Centrifuge

RPM ~f a Celllriguge Bell Sice Neededfor Cel1lrijilge Stoke's Law

Calculations 7-1 7-2

Low Gravity Solids Concentratioll in Drilling Mild Drilled Solids and Barite Lossfimll Mild Cleaner Screens

12-1

Calcli/ations .lor Solids Removal System

PCliol111GnCe

Effects of Drilled Solids

Chapter 1

introduction Many years ago, a controversy raged about the effects of drilled solids on well costs. Many thought dri11ed solids were an inexpensive substitute for weighting agents. As drilling encountered more difficult environments, however, hole problems finally became undeniably associated with excessive drilled solids.

Most rigs now process all drilling fluid sequentially in accordance with established practices. No matter what mud is used (gel-water, lignosulfonate-treated, lime-based, oil, invert emulsions, dispersed, nondispersed, etc.), drilled solids are undesirable. All drilling fluids must be treated sequentially to remove smaller and smaller drilled solids. Solids control equipment was histotically justified as an insurance policy for catastrophe prevention. Today, the more expensive drilling fluids require a low drilled solids concentration. Polymers that adhere to active solids are expensive, and these drilling fluids requlre lower concentrations of drilled solids than Iignosulfate drilling fluids. Todays environmental concerns dictate the removal of drilled solids to minimize wastes. Economics also playa part -- expensive drilling fluids can be reused if solids are removed in an efficient manner. And if wastes are minimized, so me disposal costs.

In summary, the reasons to eliminate drilled solids me many:

• • • • • •

To reduce wastes for c11I'ironll1enta/ reasons; To save money OJ1 drilling fluid costs; To save money

011

To prel1ent blo)!,

waste disposal costs;

ollIS;

To prevent stllck pipe; and To prevent excessive !Vear 011 drill bits.

The surface mud system is a processing plant to prepare mud for return to the bottom of the hole. Since all wellbores are not the same, some condition.s require more rigid mud specifications than others. TIle mud system is usually the key to drilling the least expensive footage. If the mud is impropedy treated, trouble costs can skyrocket. Most of the chapters in this manual will relate to the removal or elimination of drilled solids and other undesirable contaminants. Some of the effects of drilled solids will be discussed in the section that follows.

1-1

Chapter 1

Effects of Drilled Solids

Effects of Solids on Viscosity When solids are added to a water-based mud, some of the free water becomes chemically attached to the solids. This decreases the amount offree liquid and increases the fluid's

vi.o:;cosity. The amount of water absorbed by a given amount of solids is a function of: 1. 2. 3. 4.

The The The The

particle size of the solids; reactivity of the solids; type of drilling fluid; and type and amount of chemical additives present.

This chapter will deal with the effect of each of the above listed variables separately in the order listed, even though the effect on viscosity is the total of all four acting at the same time.

Particle Size The range of particle sizes taken into the mud stream at the bit will depend mainly on: Formation hardness; Bit type; Chip hold down; and Effectiveness of the hydraulic hole cleaning action. Even if adequate hydraulics are being used and chip hold down or differential pressure is normal, in hard formations fine chips will usually be generated. Most ofthe particles are finer than 22 microns. Another reason for fine chips is the bit type -- a diamond bil will generate smaller chips than a rock bit in hard formations. Use of a water base mud will result in smaller chips than oill11ud because of hydration and dispersion effects of the aqueous system. Use of a water base mud for drilling a soft shale fomlation will ordinarily result in very fine cuttings. With an oil mud and a cone bit, most of the cuttings are larger than 30 microns. Use of a PDC bit will produce cuttings which are typically much larger. TIle pm1ic1e size distribution is also affected by mechanical degradation. As the particles are circulated up by the mud return system, they are mashed and ground. The corners me broken off, so that continually smaller and smaller particles are being generated. Borehole stability is a factor affecting the mechanical degradation of formation solids brought to the surface by the mud system. If the hole is enlarged by erosion or sloughing, cuttings cannot be lifted from the hole efficiently. Low annular velocity in the enlarged sections of hole will cause cuttings to fall back and be ground to a finer size before reaching the surface.

1-2

Effects of Drilled Solids

Chapter 1

Figure 1-1 SU1:face Area Reslllting From Disintegration

Volume = 1".1

Surface Area = 6"

"",

l=t'",'

:!

1"

Divide Into Eight Y2" Cubes

Volume 1"

-~

Surface area 12":!

~ ~ ~ f+"',,,',,,,",

- "," "'-."'&"""!' .... eo,,,,",,

Screened SolidS Discard

11-1

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