PRESENTED TO SIR HABIB U ZAMAN MEMON

MEHRAN-UET JAMSHORO

Carbonate Acidizing & Design

Sajjad Ali Jogi (12PG146)

Carbonate Rocks

Carbonate rocks are a class of sedimentary rocks.

Composed primarily of two major types of carbonate minerals.

1.Limestone

2.Dolostone or Dolomite

Limestone

Composed of skeletal fragments of marine organisms such as coral or foraminifera.

Dolomite

An anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally CaMg(CO3)2 .

Jahanzeb Channa (12PG145)

Acidizing & Designing Acidizing involves pumping acid into a

wellbore or geologic formation that is capable of producing oil and/or gas.

Purpose of any acidizing is to improve a well’s productivity or injectivity.

Acidizing designing in which we selecte the appropriate acids, after that ready to design the treatment.

Two types of acids are most commonly used

1.Hydrochloric acid in all formation types.

2.Hydrofluoric acid in sandstones and certain shales.

Other types of acids, such as organic acids, may also be used in specialized situations

Three general categories of acid treatments are

Acid washing

Matrix acidizing

Fracture acidizing

Asadullah Khan (12PG58)

Acid Washing

Mostly used in carbonate formations

Objective is simply tubular and wellbore cleaning.

Most commonly performed with hydrochloric acid (HCl) mixtures to clean out scale (such as calcium carbonate), rust, and other debris restricting flow in the well.

Matrix Acidizing Mostly used in sandstone formations

Acid is injected into the well penetrating rock pores at pressures below fracture pressure.

Used to either stimulate a well to improve flow or to remove damage.

During this process the acids dissolve the sediments and mud solids within the pores that are inhibiting the permeability of the rock. 

Fracture Acidizing

Mostly used in carbonate formations Involves pumping highly pressurized

acid into the well, physically fracturing the reservoir rock

and dissolving the permeability inhibitive sediments.

Purpose is to restore or improve an oil or gas well’s productivity

A.Mubeen Rajput (12PG165)

Acidizing  Refers to Stimulation

Well stimulation is a well intervention performed on an oil or gas well

To increase production by improving the flow of hydrocarbons from the drainage area into the well bore.

Backflush Job

After an acid job is performed, used acid and sediments removed from

the reservoir are washed out of the well in a process called Backflush.

M.Hanif Chachar (12PG142)

Heterogeneous carbonate fields challenging to produce Carbonates can exhibit highly varying properties (e.g., porosity, permeability, flow mechanisms)

within small sections of the reservoir, making them difficult to characterize.

This involves detailed understanding of the fluids saturation,

pore-size distribution, permeability, rock texture, reservoir rock type, and natural fracture systems at different scales.

Massive hydrocarbon reserves

It is estimated that more than 60% of the world's oil and 40% of the world's gas reserves are held in carbonate reservoirs.

The Middle East, is dominated by carbonate fields, with around 70% of oil and 90% of gas reserves held within these reservoirs.

Pakistan <3

Most carbonate reservoir are present in Pakistan ( Northern areas) in which 90% of gas and 60% of oil are produces to fulfill the demand of oil/gas for our country.

But many reserves are remaining to extract or evaluate the hydrocarbon, because this reserve has an ability to fulfill the demand of the energy in Pakistan.

Conclusion

Every nation depend on economy and economy stable by profitable business,

Oil & gas sector is more profitable business in the whole world.

More exploration get more profit and stable the economy of any country.

Government interest required in exploration. Carbonate acidizing and design is required

to produce well efficiently & economically.

Refrences

Internet Wikipedia Schlumberger Petro wiki SPE Etc….