1. University of Salford
Manchester
MSc Petroleum & Gas Engineering
Geology, Exploration, Drilling and Production
Formation Damage Presentation
Lecture: Dr. G. C. Enyi
March, 2015

2. Group F Members
1. Randy Ngoua @00406814
2. Shaho Mohamedali @00406699
3. Pamela Ofili @00404903
4. Kamaran Qader @00383945
5. S.T. Jesaya @00391425
6. Tolulope Ogun @00326875
7. Uche Amarachi ONUKA @00412569
8. Kelvin Emeka Nwoha @00401037

3. • Describing its impact, Amaefule et al (1988) described it as an
expensive headache to the oil and gas industry.
• Emphasizing the uncertainties involved; Bennion (1999) describes
formation damage as the impairment of the invisible, by the inevitable
and uncontrollable, resulting in an indeterminate reduction of the
unquantifiable.
• According to Faruk, Formation damage is an undesirable operational
and economic problem. This is an impact in the reduction of oil and gas
production.
• ‘Formation Damage can cause significant decreases in well productivity
and worldwide yearly lost production due to Formation Damage is
equivalent to billions of dollars in lost revenue’.
FORMATION DAMAGE
What is Formation Damage?

4. • Solids plugging
• Clay particle swelling or dispersion
• Saturation changes
• Wettability reversal
• Emulsion blockage
• Aqueous-filtrate blockage
• Mutual precipitation of soluble salts
• Fines migration
• Deposition of paraffins or asphaltenes
• Condensate banking
• Bacterial plugging
MECHANISMS OF FORMATION DAMAGE

5. In petroleum reservoirs, some of the common mechanisms by which
formation damage occurs are categorised as follows:
• Mechanically Induced, which are also drilling induced. These will
include physical migration of In-situ fines, solids entrainment
phenomena, etc.
• Chemically Induced, reactivity clay induced damage. An example is the
common problem of high concentrations of asphaltenes when they are
destabilized.
• Biologically Induced, where bacteria as a leading cause can be
introduced into the formation during any of oil recovery operations
• Thermally Induced; mineral transformations, wettability alterations,
mineral and formation dissolution
CATEGORISATION OF MECHANISMS

6. Jaimes et al (2014) also described the mechanisms of formation damage as:
• Block in the face of the formation, produced by the tendency to form
emulsions between the oil of the well and the completion brine
• Production of inorganic scale in the porous medium during the
contact of the formation water with the completion brine
• blockage by suspended solids present in the completion brines
• Increased bacterial activity in the wellbore vicinity
• rock-fluid incompatibility due to sensitivity of the formation
minerals to the completion brine, caused by high ion exchange, causing
swelling of clays and reduction of the permeability
• increase of the water relative permeability
MECHANISMS

7. According to Yeager et al. (1997), downhole diagnostic tests that can be
conducted in the field include:
• Well-test analysis.
• Downhole video.
• Physical sampling in the form of downhole liquids and solids.
• In the open hole completions, rotary sidewall core samples.
Evaluation of Formation Damage in the Field
Hitwell E-Cam

8. Perforations (Hitwell) Oil entry through perforations (Hitwell)
Downhole Video

9. (Yeager et al., 1997) states that for open hole completed wells damage can be diagnosis
primarily be obtaining a core samples from the well bore wall in the zone of interest and
evaluating those samples to determine the formation damage
Rotary sidewall coring tool (after Yeager et al., ©1997 SPE)
Core Sample

10. A kind of temporary, partial completion of the well that provides data on
several feet or several hundred feet of producing formation
The purpose of this test is to know:
1. Type of producing fluid (oil, gas)
2. Initial reservoir pressure (pi)
3. Effective permeability ( K)
4. Skin Factor (s)
5. Ability of the well to produce oil (Q)
Well Testing (DST)

11. CONCEPT OF SKIN
• Skin is a factor that is used to
measure the extent of damage
or the decrease in formation
permeability compared to the
original permeability.
• It has no physical dimension.
• Skin can be zero (No effect),
positive or negative.
SKIN ANALYSIS

12. • For an undamaged formation:
……..equation 1
SKIN FACTOR
• For a damage formation:
………..equation 2

13. PRESSURE PROFILE FOR AN IDEAL WELL IN NEAR WELL BORE REGION

14. • Pressure drop across skin
…..equation 3
• Combining equations 1 and 2:
……… equation 4
• Skin ……….equation 5
• Components of skin effects:
….equation 6

15. PRESSURE PROFILE FOR A WELLBORE

16. Formation Damage – Laboratory Studies
A study of Formation Damage at different
drilling Environments
By
Teow Ket Seang, Issham Ismail & Abdul Razak Ismail
Faculty of chemical 7 Natural Resources Engineering
University Technology Malaysia
Aim: To study formation damage at different
drilling environment

18. Data and Graph

20. Discussion of Result
• Result shows that Drilling, Completion, Work over,
Production and Simulation are potential source of
Formation Damage.
• Others are long time contact time with drilling fluid; mud
type; differential pressure (increases fluid loss damage the
formation); annular velocity (120ft/min – 150ft/min
particles invade formation); drill pipe rotating speed and
rock permeability. Temperature at 70oC = 158oF damage
increases.

21. Conclusions
• Horizontal drilling environment causes more severe
formation damage than the deviated angle drilling.
• Understanding the physical attributes that causes
formation damage will help minimize it.

22. Recommendations
• Polymer(a foaming agent that is used in the mixing of
mud to achieve a desired purpose) should be used
minimally to avoid thermal degradation.
• Temperature should be regulated not to exceed 158OF
(70OC) to avoid drastic increase in damage.
• A higher annular velocity should be avoided.
• The differential pressure should be lowered not to reduce
the rate of permeability.

23. Formation damage reduces the rate of flow of hydrocarbons into the wellbore, and thus into the
production pipeline. By reducing formation damage, wells can flow at a higher rate, increasing the
profitability of the well by moving up the peak production years which means faster pay-outs.
This can be achieved if you know how to avoid these fluid-related causes of formation damage:
• Foreign particle invasion and plugging
• Formation clay dispersion and migration
• Chemically incompatible fluids
• Oil wetting of reservoir rock
• Emulsion and water blocking
• Fluid invasion
Minimizing formation damage
Years of Production
BarrelsofOilperYear
Reducing formation damage can help reservoirs to produce at
higher rates, resulting in faster payouts for the operator

24. N-FLOW Delayed Action Filter Cake Breaker can
effectively remove filter cake with an in-situ reaction,
leading to reduced formation damage and increased
production.
• Formation damage
• Decreased production and injection rates
‾ Increased costs
‾ Increased rig time
‾ Chemical costs
Incomplete filter cake removal may result in:
BEFORE N-FLOW
TM
AFTER N-FLOW
TM
Minimizing formation damage

25. Video of Halliburton’s Solution on completely removal of filter cakes

26. Situation: Reservoir section was drilled using Oil-based mud. Reported skin
damage was up to 25-30.
Possible causes of reduced permeability:
• Pore size distribution test were not performed
• Strong emulsifiers were used in the oil based mud
• Poor well cleaning; Inefficient filter cake removal
• Reservoir section was directly perforated with completion fluid without
using additives to prevent structure blocking
The issues of YPERGAS Project
Design of drilling and completion fluids reduces formation damage in reservoir of gas wells;
Venezuela basin, Yucal Placer Field
Case Study

27. Situation: Halliburton designed a customized solution to maximize reservoir
potential
The solution:
• Pore size distribution analysis to determine optimal size of bridging materials to
enable reservoir protection while drilling
• Determine the optimum design of the bridging package for effective sealing of
the formation
• Use the Baroid System,100% oil based mud to avoid blockage due to emulsion
within the fine porous structure of the reservoir
• Control of HP/HT filtrate to minimize invasion of fluid to the formation
• Perform effective cleaning of the wellbore using chemical train of pills using
Completion Fluid Graphic software
• Perform fluid loss control to prevent the entry of water-based fluid during the
perforating
Halliburton’s Solution
The customized fluid plan solution resulted in 30 % higher gas production per day
from the well and a skin factor of 8.
Economic Value created

28. • Horizontal drilling environment causes more severe formation
damage than the deviated angle drilling.
• Understanding the physical attributes that causes formation
damage will help minimize it.
• Create maximum production and injection potential by
effectively removing filter cakes with N-FLOWTM breakers.
Recommendations & Conclusions

29. • Jaimes, M., Castillo , R. D., Villar, A., Escobar, M., Dorado, R. & Acevedo, N., 2014. Integrated
Analysis To Identify and Prevent Formation Damage Caused by Completion Brines: A Colombian
Field Application. Venezuela, Society of Petroleum Engineers
• Renpu, W. 2011. Advanced Well Completion Engineering. Petroleum Industry Press
• Civan, F., 2007. Reservoir Formation Damage (Fundamentals, Modeling, Assessment and Mitigation)
2nd Edition.
• D.B. Bennion, F.B. Thomas, D.W. Bennion and R.F. Bietz Hycal, 1995. Mechanisms of Formation
Damage and Permeability Impairment Associated With the Drilling, Completion and Production of
Low API Gravity Oil Reservoirs. Energy Research Laboratories Ltd
• Formation damage.(2015).Petrowiki. Retrieved 13th April 2015, from
http://petrowiki.org/formation_damage
• James A. C.(2014). Skin effects. Retrieved 13th April 2015 from http://www.slideshare.net/akincraig/2-
skin-effects
• Halliburton. (2012). Design of drilling and completion fluids reduces formation damage. Retrieved
March 27, 2015, from http://www.halliburton.com/:
http://www.halliburton.com/public/bar/contents/Case_Histories/web/H09319.pdf
• Jaimes, M., Castillo , R. D., Villar, A., Escobar, M., Dorado, R. & Acevedo, N., 2014. Integrated
Analysis To Identify and Prevent Formation Damage Caused by Completion Brines: A Colombian
Field Application. Venezuela, Society of Petroleum Engineers
• Renpu, W. 2011. Advanced Well Completion Engineering. Petroleum Industry Press
• Civan, F., 2007. Reservoir Formation Damage (Fundamentals, Modeling, Assessment and Mitigation)
2nd Edition.
• D.B. Bennion, F.B. Thomas, D.W. Bennion and R.F. Bietz Hycal, 1995. Mechanisms of Formation
Damage and Permeability Impairment Associated With the Drilling, Completion and Production of
Low API Gravity Oil Reservoirs. Energy Research Laboratories Ltd
REFERENCES

30. REFERENCES
• Teow Ket Seang, Issham Ismail and Abdul Razak. 2012. A Study of Formation Damage at Different
Drilling Environment. Paper SPE 10029, 1982.
• Krueger, R. F. 2010. Overview of Formation Damage and Well Productivity in Oil Field Operations. Paper
SPE 10029, 1982.
• Jiao, Di and Sharma, M.M. 2002. Formation Damage due to Static and Dynamic Filtration of Water Mud.
Paper SPE 23823 presented at the SPE International Symposium on Formation Damage Control, Lafayette,
Louisiana.