If your water-based drilling mud is losing pH or picking up calcium hardness, two powders fix it: caustic soda raises pH and alkalinity, and soda ash removes calcium. We supply SODA ASH 25 Kg (part number RXSOL-19-1307-050) from Barka Industrial Area, Oman. Caustic soda keeps the mud alkaline so clays, thinners and polymers work as designed, and it slows corrosion of steel. Soda ash takes calcium out of the make-up water and the filtrate before it flocculates the bentonite. Most mud programmes in Oman call for both, and the order you add them in matters.
Why drilling mud pH and hardness drift on Oman wells
Water-based muds work best in an alkaline range. Many bentonite and polymer systems are held at around pH 9.5 to 10.5, but your mud programme sets the actual target for each interval. pH falls as acid gases such as carbon dioxide or hydrogen sulphide enter the mud, as fresh make-up water dilutes the system, and as organic thinners use up alkalinity.
Calcium is the second problem. Make-up water from wells in the interior can carry dissolved calcium and magnesium, and drilling through anhydrite or gypsum puts calcium sulphate straight into the mud. Once calcium passes the level your system tolerates, the bentonite flocculates, fluid loss rises and the mud thickens. Contractors on PDO concessions around Nizwa and Fahud, and on projects near Duqm, can see both problems on the same well.
What caustic soda does in the mud system
Caustic soda (sodium hydroxide, NaOH) is a strong base. In a mud system it raises pH and filtrate alkalinity (Pf), keeps lignosulphonate and lignite thinners working, and drops magnesium out as magnesium hydroxide once pH goes above about 10. A higher pH also slows corrosion of drill pipe and casing and holds hydrogen sulphide in solution as sulphide. That is one reason mud programmes for sour sections specify a higher pH together with a sulphide scavenger.
Mud engineers usually add caustic soda as a solution through the chemical barrel rather than dumping dry flakes or pearls into the pits, so the pH rises evenly. Caustic soda is classed as corrosive (GHS Skin Corrosion Category 1A, hazard statement H314: causes severe skin burns and eye damage), and dissolving it releases a lot of heat. Caustic must always be added slowly to water, never water to caustic. Wear a face shield, chemical goggles, gloves and an apron at the barrel, and keep an eyewash station close by.
If you need caustic soda alongside soda ash for a rig or mud plant, put the grade, form and quantity in your enquiry and we will confirm what we can supply.
What soda ash does and when to use it instead of caustic
Soda ash (sodium carbonate, Na2CO3) removes calcium. The carbonate reacts with dissolved calcium to form calcium carbonate, which drops out as a fine inert solid. In theory you need about 2.65 kg of soda ash for every kilogram of calcium removed, because 106 g of sodium carbonate reacts with 40 g of calcium. In practice your mud engineer works from the filtrate calcium titration and adds a small excess.
Use soda ash to pre-treat hard make-up water before you hydrate bentonite, and to treat calcium from anhydrite or gypsum. It raises pH too, but more gently than caustic soda, so it is a poor choice for pH control on its own. Keep it away from cement contamination: cement brings in lime as well as calcium, the pH is already high, and soda ash pushes it higher. Sodium bicarbonate is the usual treatment for cement.
Soda ash is safer to handle than caustic soda. It is classed as an eye irritant (GHS Eye Irritation Category 2, H319: causes serious eye irritation), so you still need goggles, gloves and dust control at the mixing hopper.
How to treat the mud on the rig
Your mud engineer sets the dose rate for each well from the test results, so we do not publish one figure for every system. The usual order is:
- Test first. Measure pH with a calibrated meter, run Pf and Mf alkalinity, and titrate filtrate calcium following the API field testing procedure your programme uses.
- Treat calcium first. Add soda ash slowly through the hopper while circulating, worked out from the calcium result.
- Adjust pH second. Bring pH up to the programme range with caustic soda solution from the chemical barrel.
- Retest after a full circulation and record the result before you treat again. Over-treating with soda ash leaves excess carbonate, which can cause high gels and poor fluid loss control.
Treating in this order stops you chasing pH with caustic while calcium is still flocculating the clay.
Our soda ash range and specifications
For drilling mud and make-up water treatment, order SODA ASH 25 Kg. Our pool and spa range also lists pH PLUS enhancer, which is sold for pool water. For rig and mud plant work, specify soda ash and contact us with your requirement.
| Item | SODA ASH 25 Kg | pH PLUS enhancer |
|---|---|---|
| Part number | RXSOL-19-1307-050 | RXSOL-19-1307-025 |
| Product range | Powder Chemical | Swimming Pool & Spa |
| Pack size | 25 Kg (as named) | Ask us |
Storage and ordering from Barka
We are based in Barka Industrial Area. Send the site location with your enquiry and we will discuss your order.
Soda ash absorbs moisture and cakes when bags are left open, so store it dry, under cover and off the ground. Caustic soda takes up moisture and carbon dioxide from the air, so keep it sealed and stored away from acids, aluminium and zinc.
For pool and water pH work along the Batinah coast, pH PLUS enhancer is also listed on our Sohar site, and on our Muscat site.
Where to buy caustic soda and soda ash in Muscat and Oman
Oman Chem (Muscat & Barka for Business Trading), Barka Industrial Area, Sultanate of Oman. Phone +968 77333599, WhatsApp +968 77333599, email muscatchem@gmail.com.
Send your requirement through our quote request page with the product name or part number, the quantity, the delivery site and the date you need it.
Frequently asked questions
Can I use soda ash instead of caustic soda to raise mud pH?
Soda ash raises pH, but slowly, and it adds carbonate to the mud. Too much carbonate causes high gels and poor fluid loss control. Use caustic soda for pH and alkalinity, and soda ash for calcium removal.
How much soda ash do I need to treat calcium?
In theory you need about 2.65 kg of soda ash per kilogram of calcium removed. Your mud engineer calculates the actual treatment from the filtrate calcium test and the system volume, then retests after circulation.
Is pH PLUS enhancer the same as soda ash?
pH PLUS enhancer (RXSOL-19-1307-025) is listed in our swimming pool and spa range. For drilling mud, order SODA ASH 25 Kg (RXSOL-19-1307-050) and contact us to confirm the right product for your application.
Do you supply an MSDS with soda ash?
Ask us when you send your enquiry and we will confirm which documents are available for your site HSE file.
Can you supply rig sites in the interior or near Duqm?
Send the site location and quantity with your enquiry and we will confirm whether and how we can supply your site.
Request a quote for soda ash and caustic soda on WhatsApp at +968 77333599.
Frequently asked questions
Can I use soda ash instead of caustic soda to raise mud pH?
Soda ash raises pH, but slowly, and it adds carbonate to the mud. Too much carbonate causes high gels and poor fluid loss control. Use caustic soda for pH and alkalinity, and soda ash for calcium removal.
How much soda ash do I need to treat calcium?
In theory you need about 2.65 kg of soda ash per kilogram of calcium removed. Your mud engineer calculates the actual treatment from the filtrate calcium test and the system volume, then retests after circulation.
Is pH PLUS enhancer the same as soda ash?
pH PLUS enhancer (RXSOL-19-1307-025) is listed in our swimming pool and spa range. For drilling mud, order SODA ASH 25 Kg (RXSOL-19-1307-050) and contact us to confirm the right product for your application.
Do you supply an MSDS with soda ash?
Ask us when you send your enquiry and we will confirm which documents are available for your site HSE file.
Can you supply rig sites in the interior or near Duqm?
Send the site location and quantity with your enquiry and we will confirm whether and how we can supply your site.
