Drilling Fluid: Water quality The system will reduce the operational stress experienced by the rig. A rig that is operating at or near its operational limits is detrimental. The ideal situation would be to accomplish the job using a minimum of available rig power. Running a rig at 75% 0f its efficiency will improve over all efficiency of an operation by as much as 40%. The Drilling contractor is in business to make money. The best way to increase the amount of money that is earned is to increase revenue and decrease costs. Another way is to charge more for your services. In competitive situations where the work is done on a bid basis this is not possible. So, is it possible to improve the efficiency of the drilling process and at the same time reduce costs? I know that it can be done but it will take some effort on the part of the drilling contractor. The effort will be to learn how fluid systems can improve the drilling operation and then teach crews how to use and implement them. MUD MIXING AND USAGE This section will delve into mud mixing and usage. The various aspects of mud mixing include water quality, products, mixing order and adequate mixing of the products. WATER QUALITY An ample supply of fresh water often simplifies the selection of the drilling fluid. Clarity alone, however, should not be accepted as evidence of purity of water, or even of its suitability for mud making. A few simple tests usually serve to define water quality. Water pH: Fresh water should have a pH of 7. Test the water with pH paper. If the pH is below 7, add soda ash to raise the pH to between 8 and 9. All fluid products will perform better in this pH range. Sulphide: Note odor. Sulphide contaminated water will have the characteristic smell of rotten eggs. Add caustic soda to raise pH to 10. If caustic soda is not available then change water source. Hardness: Test with calcium indicator. Hard water will not produce lather with bar soap. In the absence of a calcium test use the bar soap test. Add soda ash until calcium test is negative and the pH is between 8 and 9. Soda ash precipitates out the calcium as insoluble calcium carbonate, making it harmless. Salt: Change water source if tasted. There is no chemical method to remove chlorides from water. Salt will drastically reduce the yield of bentonite and increase the water loss of the fluid. If you notice severe thickening or separation of bentonite or polymer in the mixing tank, then you probably have a water quality problem. This is not always the problem since other factors can cause separation but water quality should be the first thing that should be investigated.