Reservoir Drill-In Fluids

(RDF) Why?

Reasons for RDF

• Money- What an operator spends on the completion compared to value of what is produced

Reasons for RDF

• Money- What an operator spends on the drilling and completion compared to value of what is produced

• Less damage during drilling results in a better completion.

Reasons for RDF

• The manner in which the formation is drilled affects production

• Especially the filter cake

• Minimize formation damage– #1 factor in formation damage?

•Solids

Reasons for RDF

• How is it determined that an RDF is needed?–By the reservoir characteristics

–By the completion assembly chosen

–By money

RDF, Yes or No ?• Type of completion–Does the completion require the

removal of the filter cake?– “Frac” completions do not require an

RDF since the flow channel extends well past the filter cake and near well bore region–Case/perforate completions do not

require an RDF

Type of completion

• Gravel Pack, then use RDF• Screen Completion - RDF• Expandable screens - RDF• Not case and perforate• Not frac pac

Type of completion

• If the completion requires the removal of the filter cake, then an RDF should be considered.

What is an RDF?

• Viscosified brines–Brines compatible with

formation

–Brines that can provide density

What is an RDF?• Compare a mud and an RDF–Brines compatible with

formation

–Brines that can provide density, without barite

–Brines use xc for viscosity, not clay

What is an RDF?• Compare a mud and an RDF–Mud uses barite, clay, other

products without considering removal

RDF questionnaire• Operator: _____• Location (country/state)• Offshore, swamp or land• Application (drill in fluid, high angle, slimhole,

coiled tubing, other) __Horizontal Drill In• Required density or formation pressure _____• Formation permeability _______________• Casing Depth MD/TVD and diameter _____• Hole size ____• Depth MD/TVD _

RDF questionnaire• Length of section to be drilled• Bottom hole temperature ___________• Formation type (unconsolidated sand, limestone,

other) _ • Are formation clays present? ___• Does the formation or the formation fluid react

negatively with particular brines, especially calcium? __

• Does the formation contain soluble sulfates or carbonates? ____ _____________________

• Is H2S present? __

RDF questionnaire• How will the well be completed (slotted liner,

prepacked screens, other) Provide as much detail as possible. __

• Is a non-damaging fluid critical? • Are there environmental restrictions? If so, what

are they? __________________• Formation strength _______• Will faults or fractures be encountered? _• Give a brief history of losses in the area _______• Solids control equipment available on rig Is the

formation sensitive to acid breakers? ____

Lab Work• Core plugs, developmental work• What sensitivities turn up in the lab work• What fluid to be used when drilling the

reservoir• What fluid used during completion• Compatibility of ALL fluids, equipment