### PROCEDURE FOR A MORE ACCURATE LOW-GRAVITY SOLIDS DETERMINATION

This procedure requires an oven, a pycnometer, and an electronic balance to weigh samples. A pycnometer can be made by removing the beam from a pressurized mud balance. Any type of balance may be used to determine weight; however, electronic balances are more convenient.
Determine the volume of the pycnometer:
1. Weigh the pycnometer (assembled).
2. Fill with distilled water.
3. Determine the water temperature.
4. Reassemble the pycnometer and pressurize it.
5. Dry the outside of the pycnometer completely.
6. Weigh the pycnometer filled with pressurized water.
7. Determine the density of water using a table of density/temperature of water. (See Appendix.)
8. Subtract the pycnometer weight from the weight of the pycnometer filled with water, to determine the weight of water in the pycnometer.
9. Divide the weight of water in the pycnometer by the density of water to determine the volume of the pycnometer.
Determine the density of drilled solids:
1. Select large pieces of drilled solids from the shale shaker and wash them with the liquid phase of the drilling fluid (water for water-base drilling fluid, oil for oil-base drilling fluid, and synthetics for synthetic drilling fluid.)
2. Grind the drilled solids and dry them in the oven or in a retort.2
3. Weigh the assembled, dry pycnometer.
4. Add dry drilled solids to the pycnometer and weigh.
5. Add water to the solids in the pycnometer, pressurize, and weigh.3
6. Determine the density of the NAFs using the procedure used to calibrate the pycnometer with water.
7. Determine the density of the water.
8. Subtract the weight of the dry pycnometer from the weight of the dry pycnometer containing the dry drilled solids. This is the weight of drilled solids.
9. Subtract the weight of the dry pycnometer containing the drilled solids from the weight of the water, drilled solids, and pycnometer. This is the weight of water added to the pycnometer.
10. From the temperature/density chart for water, determine the density of the water.
11. Divide the weight of the water (determined in step 9) by the density of the water. This is the volume of water added to the pycnometer.
12. Subtract the volume of the water added to the pycnometer (step 10) from the volume of the pycnometer. This is the volume of drilled solids contained in the pycnometer.
13. Divide the weight of the drilled solids (step 8) by the volume of the drilled solids (step 11). This is the density of the drilled solids.
14. Multiply the volume fraction of solids in the drilling fluid by 100 to obtain the %vol solids in the drilling fluid.

### Waste Recycle And Disposal Guidelines

Class 1 waste is any material that, because of its concentration or physicochemical characteristics, is considered “toxic, corrosive, flammable, a strong sensitizer or irritant, a generator of sudden pressure by decomposition, heat or other means, or may pose a substantial present or potential danger to human health or the environment when improperly processed, stored, transported, disposed of, or otherwise managed,” as further defined in 30 TAC 335.505 [Texas Administrative Code].

Class 2 waste is any material that cannot be described as hazardous, as class 1, or as class 3.

Class 3 wastes are inert and essentially insoluble materials, usually including, but not limited to, “materials such as rock, brick, glass, dirt and certain plastics and rubber, etc., that are not readily decomposable.”

Table 2.4
Waste Recycle/Disposal Guidelines

 M Recycle / Disposal Class Acids (undiluted) Disposal Haz Acids (spent, except hydrofluoric acid) Dilute and dispose of down sink drain – Barite, finished or crude Recycle – Bentonite clays and test fluids Recycle – Biocides Disposal per MSDS 1, 2, or Haz Bleach Dilute and dispose of down sink drain – Brines, high-density, new Reclycle – Brines, high-density, used Disposal 2 Brine/oil mixtures (emulsion testing, etc.) Disposal 1 Broken glass Disposal 2 Buffer solution Dilute and dispose of down sink drain 2 Calcium carbonate Disposal 2 Calcium chloride (solid) Disposal 2 Calcium chloride (solution) Dilute and dispose of down sink drain – Chemical spill kits Disposal per kit directions 1, 2, or Haz Cleaning service rags Disposal 2 Freshwater test fluids Recycle – Corrosion inhibitors Corrosion inhibitors 1, 2, or Haz Culture waste (filter media, gravel, etc.) Disposal 2 Cuttings, neat Disposal 2 Cuttings, with oil Disposal 1 Empty containers, hazardous Disposal 1 Empty containers,nonhazardous Disposal 2 Enzyme solutions Dilute and dispose of down sink drain – Filter cake, disks, and paper w/chrome-free mud Recycle – Field product samples Disposal 1, 2, or Haz Filter cake, disks, and paper w/chrome-containing mud Disposal Haz Freshwater test fluids Recycle – Hydrofluoric acid (handle with extreme care) Disposal Haz Hydrogen peroxide Disposal 2 Hydroxy ethyl cellulose Disposal 2 Lignosulfonate and lignite product test muds Disposal – Mercury thermometers Disposal haz Well-cleaning chemicals Disposal per MSDS 1, 2, or Haz Mud additives Disposal per MSDS 1, 2, or Haz Emulsifiers Fluid loss control Lignosulfonates Lubricants Shale inhibitors Shale stabilizers Surfactants Wetting agents Mud filtrates, oil-based/synthetic-based mud Disposal 1 Mud filtrates, water-based mud Recycle – Oil, with non-OBM constituents Disposal 1 Oil, with OBM constituents required for OBM conditioning Recycle – Oil, mixed with hazardous wastes Disposal 2 Oil-based/synthetic-based mud and wash chemicals Disposal 1 Organic peroxides Disposal 2 Paper towels used to clean up brines and muds Disposal 2 Persulfates Disposal Haz pH Buffers Dilute and dispose of down sink drain – pH test solution residuals Return to original container – Polymer slurries, mineral oil or other carrier Disposal 1 Polymers, dry Disposal 2 Potassium hydroxide (solid) Disposal Haz Potassium hydroxide (solution) Dilute and dispose of down sink drain – Retort cooked solids (chrome-containing mud) Disposal Haz Retort cooked solids (chrome-free mud) Disposal 2 Salt gel/attapulgite Disposal 2 Silver nitrate solution Dilute and dispose of down sink drain – Sodium carbonate (solid) Disposal Haz Sodium carbonate (solution) Dilute and dispose of down sink drain – Sodium hydroxide (solid) Disposal Haz Sodium hydroxide (solution) Dilute and dispose of down sink drain – Solvents, chlorinated Disposal Haz Solvents, nonchlorinated Disposal Haz Titration residue Dilute and dispose of down sink drain – Titration solution residue Dilute and dispose of down sink drain – Wash water, laboratory equipment and general Dilute and dispose of down sink drain – WBM spent titrations Dilute and dispose of down sink drain – WBM (Cl<20,000 ppm and oil <3%) Recycle – WBM (Cl >20,000 ppm or oil>3%) Disposal 1 WBM, chrome-free saltwater Disposal – WBM, chrome-containing Disposal – WBM, all others Disposal –

OBM=oil-based mud; WBM=water-based mud; MSDS=Material Safety Data Sheet

### HEALTH, SAFETY,AND ENVIRONMENT AND WASTE MANAGEMENT

1. Handling Drilling Fluid Products and Cuttings

Working with drilling fluids can be hazardous. Some drilling-fluid products emit noxious or hazardous vapors that may reach levels that exceed the maximum recommended short-term or long-term safe exposure limits. Some shale and corrosion inhibitors and some oil-base mud emulsifiers tend to produce ammonia or other hazardous volatile amines, particularly in hot areas on a rig. Other products are flammable or combustible (flash point <140F), so that they too must be handled with caution. Thus, proper ventilation is vital in the mud pit areas and around the solids-control equipment.

Various mud products, brines, cleaning agents, solvents, and base oils commonly found on drill rigs are irritating or even hazardous to body tissues. Cuttings may be coated with these materials, too. Consequently, proper protective equipment should be worn for hands, body, and eyes when working around solids-control devices, even though the protective equipment may be inconvenient or uncomfortable.

1. Drilling Fluid Product Compatibility and Storage Guidelines

Mud products and test reagents can be particularly hazardous when stored improperly. As in any well-run chemistry laboratory, materials on the rig that are chemically incompatible should be stored apart from each other, and preferably in separate spill trays (secondary containment vessels). Some general storage guidelines are given in Table 2.3. Mud products and test reagents are classified into six hazard groups, in decreasing order of hazard risk (priority)—reactive/oxidizer, toxic, flammable, acids and bases, unknown, and nonhazardous—and each group should be segregated from the others. There should be very little or no material on the rig that falls into the reactive/oxidizer category. Acids and bases, though grouped together, should be placed in separate spill trays.

Table 2.3

Hazard Classification of Chemical Reagents and Mud Products

Chemical Segregation Guidelines

Safe storage practices require that materials be separated according to chemical compatibility and hazard class. The following hazard classes should be used for segregating the waste of decreasing hazard potential. Each hazard class of chemicals should be stored in a separate secondary containment labeled with the hazard class name. The containment vessels for hazard classes containing primarily solids (e.g., nonhazardous materials) should be placed above all others. Priority 3 materials should be isolated from the flammables cabinet. The secondary containment vessel for the oxidizer hazard classes should be made of metal and sit on a metal shelf.

 Hazard Class Definition Example Water/air Materials that are potentially explosive, react violently, or generate toxic vapors when allowed to come in contact with air or water Acetyl chloride, sodium metal, potassium metal, phosphorus (red and white),inorganic solid peroxides Oxidizers,inorganic salts Specific listed inorganic compounds that react vigorously with organic materials and/or reducing agents Inorganic liquid peroxides, chlorates, perchlorates, persulfates, nitrates, permanganates, bleach Oxidizers,inorganic acids (liq) Inorganic liquids with pH<2 and strong tendency to oxidize organics Perchloric, pitric, concentrated sulfuric, bromic, hypochlorous Oxidizers, organic Specific ‘‘listed’’ organic compounds that react vigorously with organic materials and/or reducing agents Organic peroxides Toxic materials, metals Materials that contain specific ‘‘listed’’ water-soluble or volatile, nonoxidizing/ nonreacting metallic compounds that are regulated at levels below a few mg/L Metals and water-soluble compounds of arsenic, barium, beryllium, cadmium, chromium, copper, lead, mercury,thallium (e.g., chrome lignosulfonate(CLS) and materials contamined with CLS. Toxic materials, organic reagents Specific ‘‘listed’’ compounds whose concentrations in wastes are regulated at levels of 0.1 to 200 mg/L Phenol, biocides, cyanides, propargyl alcohol, carbon disulfide Flammable and combustible liquids Nonhalogenated, pourable, organic liquids with flashpoint <140_F (classes I and II) Acetone, xylene, toluene, methanol, most organic oils, oil-based mud, brine/oil mixtures, oily cuttings solvent wash,invert mud emulsifiers and wetting agents, some lubricants Halogenated liquids Halogenated organic liquids, whether flammable or not Chloroform, methylene chloride Acids, organic (liq) Organic liquids with pH<2 Acetic, butyric, formic Acids, inorganic mineral (liq) and some concentrated brines Inorganic liquids with pH<2, generally acids and certain salts Hydrochloric, hydrobromic, hydrofluoric, dilute sulfuric, phosphoric, conc. brines (low pH, e.g., bromides and iodides) Bases, organic (liq) Organic liquids with pH>12.5 Amines, hydrazines Bases, inorganic (liq) Inorganic liquids with pH>12.5 Ammonia, ammonium hydroxide, sodium hydroxide, potassium hydroxide Unclassified materials (hazardous and nonhazardous) Calorimetric ampoules (ammonia and phosphate); mercury thermometers; salt gel (attapulgite); chemical spill kits, corrosion inhibitors, field product samples, HTCE residuals, well-cleaning chemicals, some shale inhibitors, tar Nonhazardous materials, salts, clays, etc. Miscellaneous materials that do not exhibit any of the hazards identified in categories 1–10, including nonoxidizing salts with 2

3.Waste Management and Disposal

The drilling-fluid program should address environmental issues concerned with the discharge of drilling fluid, products, and removed solids. Personnel managing the solids-separation equipment must be very familiar with this part of the drilling-fluid program and have a good

understanding of governmental regulations and operator requirements. Many drilling operations have strategies in place for drilling-fluid recovery and will have established some general guidelines for the disposal of materials classified as waste. However, situations can arise that present the engineer managing the solids-control equipment with the issue of whether to discard or recycle some types of waste and how to do it. If disposal costs are not a factor, then all waste can be disposed of and treated, if necessary, onsite or sent to a processor offsite. However, if it is possible to recycle some of the products to the mud system, it may prove economical to do so [Hollier et al]. Table 2.4 contains some general guidelines approved in the state of Texas for recycling and disposing of waste from a drilling operation. Definitions used in those guidelines for hazardous, class 1, class 2, and class 3 wastes are given below. Solid waste is classified as hazardous by the U.S. Environmental Protection Agency if it meets any of the following four conditions:

. The waste exhibits ignitability, corrosivity, reactivity, or toxicity.

. The waste is specifically listed as being hazardous in one of the four tables of 40 CFR 261: [Code of Federal Regulations]

1. Hazardous wastes from nonspecific sources (40 CFR 261.31)
2. Hazardous wastes from specific sources (40 CFR 261.32)
3. Acute hazardous wastes (40 CFR 261.33(e))
4. Toxic hazardous wastes (40 CFR 261.33(f)).

. The waste is a mixture of a listed hazardous waste and a nonhazardous waste.

. The waste has been declared to be hazardous by the generator.