Contamination, drilling mud

The Biothemi Process uses the patented C-G Process approach for drying and solvent extraction to separate oil-soluble contaminants from liquid, solid, or slurry wastes. The C-G Process has been used extensively over the last 30 years to dry and extract compounds from a variety of wet, oily solids (D105453, pp. 1, 23). The C-G Process has been evaluated on the demonstration level by the U. S. Environmental Protection Agency (EPA) for treating petroleum-contaminated drilling mud from a Superfund site. 

An analysis of technology costs for the C-G process was inclnded in a report published by the U. S. (EPA) in 1992. The cost estimate for treating petrolenm-contaminated drilling mud waste is extrapolated from test results obtained in EPA laboratory tests. The estimate assnmes treatment of 23,000 tons (21,000 metric tons) at a rate of 1.4 tons (1.3 metric tons) per honr. The EPA per ton cost estimate is 523. Of this amonnt, C-G process-specific cost was 221 and site-specific cost was 302. Of the site-specific costs, 240 was for incinerating the recovered oil. Costs presented in this analysis were reported as order-of-magnitnde estimates (i.e., —30 to 4-50%). Other assnmptions nsed in this estimate are inclnded in Case Stndy 1 (D105453). 

Petroleum and Natural Gas. Over 90% of the 428,000 t of caustic soda used in the petroleum and natural gas industry is used to process oil and gas into marketable products, especially by removing acidic contaminants. The remainder is used primarily to decrease corrosion of drilling equipment and to increase the solubiUty of drilling mud components by maintaining an alkaline pH (6). 

The mud contamination with chlorides results from salt intrusion. Salt can enter and contaminate the mud system when salt formations are drilled and when saline formation water enters the wellbore. 

The determination of the excess cement slurry should be carefully calculated too little and the cement seal at the liner hanger is contaminated with drilling mud too much and there are problems removing it. 

Salts are sometimes added to drilling muds to obtain certain desired mud characteristics. They can also enter the drilling fluid through contamination by addition of makeup water, formation-fluid inflow, and drilled formations such as salt domes, gypsum or anhydride formations. In freshwater systems, if salt contamination reaches undesirable levels, the following methods should be considered for control. 

Synthetic polymers and natural polymers suitable for drilling muds are listed in Tables 1-7 and 1-8, respectively. Polyacrylamides are eventually hydrolyzed in the course of time and temperature. This leads to a lack of tolerance toward electrolyte contamination and to a rapid degradation inducing a loss of their properties. Modifications of polyacrylamide structures have been proposed to postpone their thermal stability to higher temperatures. Monomers such as AMPS or sulfonated styrene/maleic anhydride can be used to prevent acrylamide comonomer from hydrolysis [92]. 

Uintaite is not easily water wet with most surfactants. Thus, stable dispersions of uintaite are often difficult to achieve, particularly in the presence of salts, calcium, solids and other drilling fluid contaminants and/or in the presence of diesel oil. The uintaite must be readily dispersible and must remain water wet otherwise it will coalesce and be separated from the drilling fluid, along with cuttings at the shale shaker or in the circulating pits. Surfactants and emulsifiers are often used with uintaite drilling mud additives. 

Providing for storage or disposal of contaminated materials (e.g., decontamination solutions, disposable equipment, drilling muds and cuttings, well-development fluids, well-purging water, and spill-contaminated materials)... 

OnSite Technology, L.L.C. (OnSite) has developed the portable indirect thermal desorption (ITD) system for the treatment of hazardous wastes. The ITD 6000 uses a rotating, heat-jacketed closed barrel to vaporize hydrocarbons from contaminated soils and drilling mud, allowing the hydrocarbons to be recovered while cleaning the contaminated sediment. The technology is commercially available. 

The vendor claims that ITD technology removes more than 99.9% of the hydrocarbons from contaminated sods, allowing customers to use more efficient, oil-based drilling muds and recycle the reclaimed hydrocarbons from the drill cuttings. 

The EPA s estimate for the Carver-Greenfield process assnmed treatment of 23,000 ton of drilling mud contaminate with petrolenm wastes. The total cost estimate was 523/wet ton, with 221/ton allocated to technology costs. Site costs were estimated to be 302/ton, including 240/ton for incineration of contaminated residnals. This estimate did not include regulatory, permitting, and analytical costs becanse of their variability (D11243W, p. 5.4). 

Thermotech Systems Corporation (Thermotech) has patented a thermal desorption, two-stage tandem soil remediation unit (TDU) that treats and desorbs light and heavy hydrocarbons from contaminated soils, clays, and drilling muds. Thermotech s TDU does not incinerate soil, but rather cleans and recycles it. The technology has been commercially available since 1991. 

The applications of barium compounds are varied and include use as oil-drilling mud. Barium carbonate is sometimes employed as a neutralizing agent for sulfuric acid and, because both barium carbonate and barium sulfate are insoluble, no contaminating barium ions are introduced. The foregoing application is found in the synthetic dyestuff industry. 

Two test wells, H-15D and LP-1, were drilled in areas known to contain other wells having high arsenic levels (Fig. 1, 2). To minimize possible contamination from drilling mud, city water (H-15D) or ground water from a nearby well (LP-1), was used to circulate rock cuttings. Water samples were collected at 15.7 m intervals using a pump and packer system, with selected zones of interest sampled in packed 1.37 m or 5.33 m intervals, using a similar protocol. 

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