The purpose of this research was to determine and evaluate the chemical properties of drilling waste from five well sites in Central −1 and Eastern Poland. It was found that spent drilling fluids can contain high values of nickel and mercury (270 and 8.77 mg kg −1 respectively) and can exceed the maximum permissible limits recommended by the EC regulations for safety of soils (75 mg kg −1 for nickel and 1.5 mg kg for mercury). The heavy metal concentrations in the studied drill cuttings did not exceed the maximum permissible limits recommended by the EC regulation. Drilling wastes contain macroelements (e.g., calcium, magnesium, and potassium) as well as trace elements (e.g., copper, iron, zinc, and manganese) that are essential for the plant growth. It was stated that water extracts of drilling fluids and drill cuttings, according to anions presence, had not any specific constituents of concern based on FAO irrigation guidelines, the USEPA WQC, and toxicity values. X-ray diffraction analysis was used to understand the structure and texture of waste drilling fluid solids and drill cuttings. Analysis of the mineralogical character of drilling fluid solids revealed that they contained calcite, quartz, muscovite, sylvite, barite, dolomite, and orthoclase. Drill cuttings contained calcite quartz, muscovite, barite, dolomite, and barium chloride. . . . . . Keywords Drilling fluid Cuttings Microelements Macroelements Heavy metals Recycling Introduction walls of the hole, while lignosulphonates and lignites are used to keep the mud in a fluid state. Drilling fluid can contain toxic Drilling fluids (drilling muds) are one of the primary wastes substances and are therefore considered environmentally dam- generated from drilling operations. They are used to lubricate aging (Fink 2011; Drilling Waste Management Information and the cool drilling apparatus, transport drill cuttings to the System 2017). Drill cuttings are produced as the rock is bro- surface, and seal porous geologic formation (Yao and Naeth ken by the drill bit advancing through rock or soil. They are 2014; Fink 2011). Drilling fluids are made up of a base fluid made up of ground rock coated with a layer of drilling fluid. (water, diesel or mineral oil, or a synthetic compound), Few studies have addressed the impact of disposal of spent weighting agents (e.g., barium sulphate), bentonite clay, drilling fluids on soil-plant-water systems. Some researchers lignosulphonates and lignites, and various additives that serve found that high soluble salts, heavy metals, and petroleum specific functions. Bentonite clay is used in drilling fluids to residue contents in drilling fluids were detrimental to soil qual- remove cuttings from the well and to form a filter cake on the ity and plant growth (McFarland et al. 1994; Wojtanowicz 2008; Zvomuya et al. 2011). Others found positive or no im- pact from drilling fluid applied at low rates in coarse-textured Responsible editor: Philippe Garrigues soils in arid regions due to pH value increases, potential mi- cronutrient addition, and improved soil properties (Lesky et al. * Marzena Mikos-Szymańska email@example.com 1989; Bauder et al. 2005; Yao and Naeth 2014, 2015). Few studies have focused on the release of toxic elements from oil well drill cuttings and their effect on soil and aquatic ecosys- Fertilizer Department, New Chemical Syntheses Institute, Al. Tysiąclecia Państwa Polskiego 13A, 24-110 Puławy, Poland tems (Magalhães et al. 2014; Purser and Thomsen 2012). The management technologies and practices for drilling New Chemical Syntheses Institute, Inorganic Chemistry Division BIChN^ in Gliwice, Ul. Sowińskiego 11,, 44–101 Gliwice, Poland waste can be grouped into three major categories: waste Environ Sci Pollut Res minimization, recycle/reuse, and disposal. The volume of dril- respectively), and Łochów in Masovian Vivodeship (DF5 and ling waste released into the environment should be reduced for C5, respectively) shale gas drilling concessions. example by directional drilling that generates smaller volume of cuttings compared to the conventional one or by the use of Sample preparation techniques that need less drilling fluids and use alternative clean energy (solar, hydro, wind) for running drilling activities A collected sample of drilling fluid was dried at 50 °C to obtain (Sharif et al. 2017). Recycling involves the conversion of a solid; afterwards, it was grounded and homogenized. A drill wastes into usable materials that can be used to make new cuttings’ sample was dried in a laboratory oven at 105 °C, in products. The waste can be used as substitutes for commercial the amount of 1.2 kg. The dried sample was preliminary products or as a feedstock in industrial processes (Zhang et al. crushed and then grounded using a laboratory ham mill. 2016;Sharifet al. 2017). Disposal is the least preferred waste For XRD analysis, a collected drilling fluid, in suspension, management option from the environmental point of view. was dried at 50 °C in order to obtain solids. Cuttings were Cuttings’ reinjection (Shadizadeh et al. 2011), onsite burial dried in a laboratory oven at 105 °C in order to obtain a solid. (Onwukwe and Nwakaudu 2012), waste pits, landfills, land- Dried samples were crushed in a porcelain mortar and sieved farming/land-spreading (Saint-Fort and Ashtani 2013), biore- to obtain a homogenous powder with grains under 50 μm. mediation, composting (Paladino et al. 2016), and vermi- culture (Adekomaya 2014; Sharif et al. 2017) are the examples Analytical methods of disposal methods for onshore operations. In Poland, the first borehole, aimed at the exploration of Analytical methods, used for determination of metal contents natural gas from shales, was drilled in the year 2010. Natural in drilling fluid and cuttings samples by ICP-OES and mercu- gas from shale accumulations is released through drilling ry content by CV-AAS, are described in previous article holes reaching depths of several thousand meters. Hydraulic (Gluzińska et al. 2017). fracturing operations generate a considerable amount of waste (Pyssa 2016). Ion chromatography The purpose of this research was to determine and evaluate the chemical properties of drilling waste from shale gas dril- Equipment ling activities in Central and Eastern and South-Eastern Poland. The objectives of this research were (i) contrast chem- Chloride and sulphate analyses in drilling wastewater extracts ical characteristics of drilling waste samples; (ii) identify spe- were conducted using an ion chromatograph ICS-3000 cific constituents of concern (COCs) and differences in anion (Dionex Company) working in an external water mode. concentrations in water extracts of drilling waste by comparing Chromeleon 6.7 Chromatography Management Software them with FAO guidelines for agriculture uses, USEPA water (Dionex) was used for the system control and data processing. quality criteria for surface discharge, and toxicity values for D. magna and P. promelas; and (iii) to determine the mineralog- Reagents and solutions ical compositions of drilling fluid solids and drill cuttings. − − − 3− − Multi-Component Anion Mix 4, (F ,Br ,Cl ,PO ,NO , 4 3 2− SO ,c=100 μg/ml) (Acculon) as a reference standard for Material and methods quantitative determination of studied anions was used. Water, 18.2 MΩ WaterPro PS Labconco, free of particles of diameter Samples >0.2 μm was used. As an eluent, 30 Mm NaOH (Fluka; sodium hydroxide; puriss. P.a. ACS; ≥ 98.0%; pellets) was The object of analysis covers Silurian and Ordovician shale used. Calibration standard solutions for those ions determina- formations in Poland (Porębski et al. 2013; Jarzyna et al. tions were prepared from the standard solution by dissolution 2017). Samples of the spent bentonite potassium drilling fluid with deionized water. A calibration concentration range for and drill cuttings were collected from well sites located in determined ions was 0.1; 0.5; 2; 5 mg/dm . Central and Eastern Poland in 2015–2016. Samples came from five different locations of drilling sites. Drilling fluids Sample preparation and drill cuttings were collected as two separate samples. Samples of drilling fluid and cuttings (DF1 and C1, respec- Samples of water extracts of drilling waste, weighing about 1– tively) were from Dobryniów in Lublin Vivodeship, 2 g, were dissolved in water in a 250-ml volumetric flask and Kościaszyn in Lublin Vivodeship (DF2 and C2, respectively), was made up to the mark. An analytical sample was prepared Przemyśl in Subcarpathian Voivodeship (DF3 and C3, respec- from the solution by dilution with water in a ratio 1:100. tively), Lubliniec in Subcarpathian Voivodeship (DF4 and C4, Analysis was carried out in three parallel repetitions. The Environ Sci Pollut Res diluted sample was passed through a 0.45-μmmembrane filter Results and discussion just before injection to the chromatographic column. Metal contents by ICP-OES and mercury content Chromatograph operating conditions by CV-AAS Conditions of carried out chromatographic analysis are pre- The chemical characteristics of drilling waste depend largely sented in Table 1. on geological factors related to the shales deposits and on dif- ferent drilling techniques used at the well sites, namely the type Comparison of anions in water extracts of drilling of muds (e.g., water-, oil-, or synthetic-based muds), and the waste with water use criteria method of drilling (e.g., traditional or pneumatic). Thus, dril- ling waste from every drilling activities has its own chemical A risk-based approach was used to identify specific constitu- characteristics. The elemental composition of drilling waste ents of concern (COCs) in the water extracts of drilling fluid was determined by ICP-OES and mercury (Hg) by CV-AAS. solids and water extracts of cuttings. COCs were identified as Elements, such as cobalt (Co), cadmium (Cd), chromium (Cr), anions in water extracts of drilling solid waste at sufficient copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn), concentrations to pose potential risks to receiving system biota aluminum (Al), barium (Ba), calcium (Ca), iron (Fe), magne- and crops. Comparison of anion concentrations to the Food sium (Mg), and mercury (Hg) in drilling fluid and drill cuttings and Agriculture Organization of the United Nations (FAO) samples were detected. Ca was the most predominant element −1 numeric standards for irrigation, United States Environment in drilling waste with the concentration exceeding 50 g kg . −1 Protection Agency (USEPA) water quality criteria (WQC), Ca content in drilling fluid ranged from 53.4 to 131 g kg and toxicity values for D. magna and P. promelas was used (Table 1). In other study, Ca level in drilling wastes (oil- −1 to discern COCs in the water extracts of drilling waste solids based fluids and cuttings) was on average 87.3 g kg (Ayers and Westcot 1994;USEPA 2007). (Adekunle et al. 2013). Co content in drilling fluids ranged −1 from14to44mg kg . Kisic et al. (2009) conducted survey Powder X-ray diffraction of 20 drilling fluid samples taken from the central waste pit of oil/gas fields. In case of heavy metals, the samples contained The XRD measurements of samples were performed on a elements such as Cd, Hg, Pb, As, Ni, Cu, Cr, Zn, Ba, and Ca PANanalytical Empyrean system (Bragg-Brentano geometry) that contained on average 9.6, 3.8, 219, 41.2, 34.3, 31.2, 57.8, 3D −1 −1 equipped with a PIXcel detector using Cu Kα radiation (λ = 206, and 2373 mg kg , and 9.03 g kg , respectively. The 1.542 Å) and operating at 40 Kv and 40 Ma. The samples were level of Cd in drilling fluids was significantly lower (0– −1 scanned between 10 < 2θ < 70°, with the step size 0.01° 2θ 0.26 mg kg ) compared to that determined in the study −1 and time/step 30 s. The quantity analysis of crystallographic (8.8–11.0 mg kg of Cd). A maximum level of Pb in the −1 drilling fluid (190 mg kg ) was similar to the average content phases was automatic using Rietveld’s method with Brindley corrections for micro-absorption and manual corrections of of Pb in the study (Kisic et al. 2009). In our study, Ni content in −1 results for better fitting parameters. The line broadening was drilling fluids ranged from 16 to 270 mg kg whereas in the determined in the High-Score Plus software. The pseudo-Voigt samples evaluated by Kisic et al. (2009) ranged from 27.5 to −1 function for peak size approximations was used. 39.5 mg kg . Cu content in studied drilling fluids ranged from −1 40 to 66 mg kg whereas Cu content in drilling fluid samples −1 rangedfrom26.8to41.6mgkg in the mentioned study. Cr Table 1 Chromatographic analysis conditions and Zn contents in drilling fluids were similar (31–80 and 60– Analytical column + guard column AS11-HC (4 × 250 mm) −1 200 mg kg , respectively) to those contents in drilling fluids + AG11-HC (4 × 50 mm) −1 from waste pit in Croatia (47.2–68.2 mg kg of Cr and 139– −1 295 mg kg of Zn) (Kisic et al. 2009). Drilling waste from Eluent 30 Mm NaOH other well sites in Poland contained toxic heavy metals such as Eluent flow rate 1.5 ml/min −1 −1 Cr (17.2–35.6 mg kg ), Ni (22.9–46.8 mg kg ), Zn (31.6– Pressure in the column ~ 1940 psi −1 −1 276.0 mg kg ), Pb (11.5–211.5 mg kg ), and Cu (28.3– Injection volume 25 μl −1 160.1 mg kg )(Śliwka et al. 2012). Moreover, Śliwka et al. Column operating temperature 30 °C (2012) stated that the majority of samples (five from eight Conductometer cell temperature 35 °C drilling waste samples) did not exceed dangerous level of total Suppression type ASRS 300–4mm content of toxic heavy metals for soil environment Suppressor current intensity 112 Ma −1 (150 mg kg d m). Research conducted by Steliga and Detection Conductometric Uliasz (2014) showed that bentonite drilling fluids after a co- Analysis time 10 min −1 −1 agulationcontained985mgkg of Ba, 201.9 mg kg of Pb, Environ Sci Pollut Res 0.1 Co Cd Cr Cu Mn Ni Pb Zn Al Ba Ca Fe Mg Hg DF1 DF2 DF3 DF4 DF5 EC Regulaon Fig. 1 Concentrations of metals in drilling fluids from five different drilling locations in Poland −1 −1 −1 86.6mgkg of Cu, 25.3mgkg of Cr, 20.1 mg kg of Ni, and (Ca, Mg, K, Na), microelements (Cu, Co, Fe, Mn, Zn, As, Al, −1 1.8 mg kg of Hg. Figure 1 shows metal contents in drilling Ba), and heavy metals (Cr, Cd, Pb, Ni, Hg). Ca content in −1 fluids from five different drilling locations. Taking into account, cuttings ranged from 51.1 to 116 g kg , Mg content ranged −1 the EC Regulation No. 86/278/EEC, only one of the five samples from 8.19 to 20.2 g kg , and K content ranged from 16.0 to −1 (DF2) exceeded the maximum permissible limit values (30– 34.0 g kg (Table 3). Na content was determined only in the −1 −1 −1 75 mg kg ) for Ni content (270 mg kg ) and one of the five one drill cuttings sample and it was 3.68 g kg .Comparing −1 samples (DF5) contained a high amount of Hg (8.77 mg kg ) the concentrations of contaminants in drill cuttings with re- −1 comparing to limit values for soils (1–1.5 mg kg )(thePL search results obtained by other researchers in the world Regulation of the Minister of Environment 2016). (Table 4), it was stated that Al contents in drill cuttings −1 The characteristics of drill cuttings, including metal concen- (30,600 to 62,500 mg kg )werehigherthan in cuttingsfrom −1 trations, are showed in Table 3. They contain macroelements Brazil (23,000 mg kg ) (Junior et al. 2017). As content in drill 0.1 Co Cd Cr Cu Mn Ni Pb Zn Al Ba Ca Fe Mg Hg C1 C2 C3 C4 C5 EC Regulaon Fig. 2 Concentrations of metals in drill cuttings from five different drilling locations in Poland -1 -1 Concentrations (mg·kg ) Concentrations (mg·kg ) (Logarithmic Scale) (Logarithmic Scale) Environ Sci Pollut Res Table 2 Chemical analysis of drilling fluids (Central and Eastern Poland, 2015–2016) Metal contents Method DF1 DF2 DF3 DF4 DF5 PL Regulation*) EC Regulation**) I II III IV Soils; pH = 6–7 Macroelements −1 Ca (g kg ) ICP-OES 44.7 ± 6.7 53.4 ± 8.0 131.0 ± 19.6 99.6 ± 14.9 100.7 ± 15.2 −1 Mg (g kg ) ICP-OES 10.7 ± 1.6 12.2 ± 1.8 5.8 ± 0.9 7.0 ± 1.1 6.25 ± 0.9 −1 K(gkg ) ICP-OES 14.7 ± 2.2 53.5 ± 8.0 53.2 ± 8.0 59.7 ± 9.0 60.4 ± 9.1 −1 Na (g kg)ICP-OES ––– – 11.4 ± 1.7 Microelements −1 Cu (mg kg ) ICP-OES 66.0 ± 9.9 44.0 ± 6.6 50.0 ± 7.5 40.0 ± 6.0 45.8 ± 6.9 200 100–300 300 600 50–140 −1 Co (mg kg ) ICP-OES 44.0 ± 6.6 19.0 ± 2.9 16.0 ± 2.4 14.0 ± 2.1 – −1 Fe (g kg ) ICP-OES 26.5 ± 4.0 25.0 ± 3.8 14.6 ± 2.2 15.9 ± 2.4 16.1 ± 2.4 −1 Mn (mg kg ) ICP-OES 390.0 ± 58.5 340.0 ± 51.0 280.0 ± 42.0 500.0 ± 75.0 460.0 ± 69.0 −1 Zn (mg kg ) ICP-OES 74.0 ± 11.1 200.0 ± 30.0 180.0 ± 27.0 60.0 ± 9.0 78.9 ± 11.8 −1 As (mg kg)ICP-OES ––– – 8.05 ± 1.2 25 10–50 50 100 −1 Al (g kg ) ICP-OES 43.3 ± 6.5 35.6 ± 5.3 23.3 ± 3.5 26.7 ± 4.0 18.3 ± 2.7 −1 Ba (g kg ) ICP-OES 19.6 ± 2.9 27.2 ± 4.0 83.6 ± 12.5 66.0 ± 9.9 61.1 ± 12.2***) 0.4 0.2–0.6 1.0 1.5 Heavy metals −1 Cr (mg kg ) ICP-OES 69.0 ± 10.4 80.0 ± 12.0 38.0 ± 5.7 40.0 ± 6.0 31.0 ± 4.6 200 150–500 500 1000 −1 Cd (mg kg ) ICP-OES < 0.005 < 0.005 < 0.005 < 0.005 0.26 ± 0.04 2 2–510 15 1–3 −1 Pb (mg kg ) ICP-OES 18.0 ± 2.7 190.0 ± 28.5 140.0 ± 21.0 17.0 ± 2.6 27.1 ± 4.1 200 100–500 500 600 50–300 −1 Ni (mg kg ) ICP-OES 16.0 ± 2.4 270.0 ± 40.5 16.0 ± 2.4 19.0 ± 2.9 67.8 ± 10.2 150 100–300 300 500 30–75 −1 Hg (mg kg ) CV-AAS 0.10 ± 0.02 0.40 ± 0.09 1.00 ± 0.22 – 8.77 ± 1.93 5 2–510 30 1–1.5 *)Maximum permissible limits of heavy metal contents in soils (depth 0–0.25 m below the ground level) for I–IV class of soil according to the Regulation of the Minister of Environment (Poland), 2016 **)Maximum permissible limits for heavy metal contents in soils, pH = 6–7 according to Directive 86/278/EEC ***)A total Ba content determined by XRD –Not determined Environ Sci Pollut Res Table 3 Chemical analysis of drill cuttings (Central and Eastern Poland, 2015–2016) Metal contents Method C1 C2 C3 C4 C5 PL Regulation*) EC Regulation**) III III IV Soils;pH=6–7 Macroelements −1 Ca (g kg ) ICP-OES 51.7 ± 7.8 85.3 ± 12.8 95.2 ± 14.3 51.1 ± 7.7 116.0 ± 17.4 −1 Mg (g kg ) ICP-OES 20.2 ± 3.0 18.8 ± 2.8 13.0 ± 0.2 12.9 ± 1.9 8.19 ± 1.2 −1 K(gkg ) ICP-OES 24.0 ± 3.6 34.0 ± 5.1 27.2 ± 4.1 29.1 ± 4.4 16.0 ± 2.4 −1 Na (g kg)ICP-OES –––– 3.68 ± 0.6 Microelements −1 Cu (mg kg ) ICP-OES 66.0 ± 9.9 64.0 ± 9.6 85.0 ± 12.8 41.0 ± 6.2 53.0 ± 8.0 200 100–300 300 600 50–140 −1 Co (mg kg ) ICP-OES 27.0 ± 4.1 19.0 ± 2.9 20.0 ± 3 12.0 ± 1.8 – −1 Fe (g kg ) ICP-OES 36.5 ± 5.5 34.7 ± 5.2 28.2 ± 4.2 34.7 ± 5.2 27.3 ± 4.1 −1 Mn (mg kg ) ICP-OES 590.0 ± 88.5 410.0 ± 61.5 570.0 ± 85.5 730.0 ± 109.5 470.0 ± 70.5 −1 Zn (mg kg ) ICP-OES 71.0 ± 10.7 89.0 ± 13.4 160.0 ± 24.0 66.0 ± 9.9 86.1 ± 12.9 −1 As (mg kg)ICP-OES –––– 8.1 ± 1.2 25 10–50 50 100 −1 Al (g kg ) ICP-OES 62.5 ± 9.4 55.6 ± 8.3 52.5 ± 7.9 60.7 ± 9.1 30.6 ± 4.6 −1 Ba (g kg ) ICP-OES 61.6 ± 9.2 8.6 ± 1.3 58.4 ± 8.8 9.2 ± 1.4 81.4 ± 16.3***) 0.4 0.2–0.6 1.0 1.5 Heavy metals −1 Cr (mg kg ) ICP-OES 82.0 ± 12.3 110.0 ± 16.5 72.0 ± 10.8 81.0 ± 12.2 140.0 ± 21.0 200 150–500 500 1000 −1 Cd (mg kg ) ICP-OES < 0.005 < 0.005 < 0.005 < 0.005 0.4 ± 0.1 2 2–510 15 1–3 −1 Pb (mg kg ) ICP-OES 45.0 ± 6.75 250.0 ± 37.5 86.0 ± 12.9 42.0 ± 6.3 28.1 ± 4.2 200 100–500 500 600 50–300 −1 Ni (mg kg ) ICP-OES 36.0 ± 5.4 35.0 ± 5.3 24.0 ± 3.6 37.0 ± 5.6 70.1 ± 10.5 150 100–300 300 500 30–75 −1 Hg (mg kg)CV-AAS – 0.10 ± 0.02 0.50 ± 0.11 – 0.77 ± 0.17 5 2–510 30 1–1.5 *)Maximum permissible limits of heavy metal contents in soils (depth 0–0.25 m below the ground level) for I–IV class of soil according to the Regulation of the Minister of Environment (Poland), 2016 **)Maximum permissible limits for heavy metal contents in soils, pH = 6–7 according to Directive 86/278/EEC ***)A total Ba content determined by XRD –Not determined Environ Sci Pollut Res −1 cuttings (C5) was 8.1 mg kg and in cuttings from the USA (Leonard and Stegemann 2010) and Nigeria (Kogbara et al. −1 2016) was 5 and 10.8 mg kg , respectively. Ba contents in drill cuttings ranged from 8600 to 81,400 and the drill cuttings from Brazil (Junior et al. 2017) and from the USA (Leonard −1 and Stegemann 2010) contained 18,000 and 51,500 mg kg −1 of Ba, respectively. Cd contents (0–0.4 mg kg ) were smaller −1 than those in cuttings from the USA (21 mg kg )(Leonard and Stegemann 2010). Co content in cuttings ranged from 12 −1 to 27 mg kg and in the cuttings from the USA, it was −1 14 mg kg . In our study, Cr contents in drill cuttings ranged −1 from 72 to 140 mg kg , and in the study conducted by −1 Kujawska and Cel (2017), they contained 65.76 mg kg of Cr. The ranges of Cr contents were similar to the Cr content in −1 drill cuttings from the USA (106 mg kg )and higher than Cr −1 contents in cuttings from Nigeria (0.01 to 0.65 mg kg ) (Gbadebo et al. 2010; Kogbara et al. 2016). Cu contents in −1 cuttings ranged from 41 to 85 mg kg and were similar to −1 those in cuttings from the USA (44 mg kg ). They were higher than Cu contents in cuttings from Nigeria (0– −1 0.16 mg kg )(Gbadebo et al. 2010). Kogbara et al. (2016) determined the Cu content in drill cuttings from Nigeria and −1 they contained 114 mg kg of Cu. In our study, Mn contents −1 in cuttings ranged from 410 to 730 mg kg , drill cuttings from −1 the USA contained 345 mg kg of Mn, whereas drill cuttings from Nigeria contained very small amounts of Mn (0.26– −1 3.45 mg kg ). It was stated that drill cuttings from Polish well sites were characterized by the higher ranges of Ni, Pb, and Zn −1 content (24–70.1, 28.1–250, and 66–160 mg kg , respective- ly) compared to drill cuttings from Nigeria (0–2.12, 0–2.19, and 0.02–0.55, respectively) (Gbadebo et al. 2010). The study of contaminant contents in drill cuttings from Nigeria conduct- ed by Kogbara et al. (2016) revealed that they contained −1 −1 −1 10.5 mg kg of Ni, 178 mg kg of Pb, and 196 mg kg of Zn. Studies of metal contents in drill cuttings from the USA (Leonard and Stegemann 2010) showed that they contained −1 −1 −1 38 mg kg of Ni, 150 mg kg of Pb, and 82 mg kg of Zn. The mentioned researchers did not determine the Hg con- tents in drill cuttings. The results showed the trend of higher metal contents such as Mg, Cu, Fe, Mn, Zn, Al, Cr, Pb, and Ni in the drill cuttings than in drilling fluids and it was confirmed by other re- searchers (Gbadebo et al. 2010; Veritas 2000) (Figs. 1 and 2; Tables 2 and 3). To determine and identify specific metal species and their binding forms in drill cuttings, the chemical fractionation should be used. The heavy metals and nutrients mobility are connected with the solubility of their forms. The sequential extraction analysis can be used in order to deter- mine the mobility of metals from drill cuttings. In the Community Bureau of Reference (BCR) method procedure, the following fractions can be distinguished: exchangeable (the most mobile metals), reducible (elements absorbed or co-precipitated with Fe and Mn oxides, medium mobility), Table 4 Comparison of the range of contaminant concentrations in the drill cuttings with research data conducted by other researchers Contaminants Metal contents in drill cuttings Kujawska and Cel (2017) Junior et al. (2017) Leonard and Stegemann (2010) Gbadebo et al. (2010) Kogbara et al. (2016) Poland Poland Brazil USA Nigeria Nigeria −1 Al (mg kg ) 30,600–62,500 – 23,000 –– – −1 As (mg kg)8.1 –– 5 – 10.8 −1 Ba (mg kg ) 8600–81,400 1911.33 18,000 51,500 –– −1 Cd (mg kg )0–0.4 –– 21 –– −1 Co (mg kg )12–27 0.2 – 14 –– −1 Cr (mg kg)72–140 65.76 – 106 0.01–0.65 0.22 −1 Cu (mg kg )41–85 104.29 – 44 0–0.16 114 −1 Mn (mg kg ) 410–730 469 – 345 0.26–3.45 – −1 Ni (mg kg)24–70.1 21.75 – 38 0–2.12 10.5 −1 Pb (mg kg ) 28.1–250 41.92 – 150 0–2.19 178 −1 Hg (mg kg )0.1–0.774 –– – – – −1 Zn (mg kg)66–160 62.1 – 82 0.02–0.55 196 −1 Fe (mg kg ) 27,300–36,500 14,370 27,000 26,400 1.95–714 – –Not determined Environ Sci Pollut Res Table 5 Comparison of the range of anions in water extracts of drilling waste with research data conducted by other researchers and with irrigation guidelines, surface water discharge criteria (SDW), and toxicity values for D. magna and P. promelas −1 Samples Anions (mg kg ) − − − − 3− 2− Br Cl F NO PO SO 3 4 3 DF5 ND 24.40 ND ND ND 0.87 C5 ND 5.70 ND ND ND 6.37 HFWE 851 75,100 ND ND – 199 WP 15.9 9000 ND ND – 2600 SGPW ND-10600 48.9–212,700 ND-33 ND-2670 ND-5.3 ND-3663 TGSPW – 52–216,000 –– – 12–48 CBMPW 0.002–300 0.7–70,100 0.05–15.22 0.002–18.7 0.05–1.5 0.01–5590 NGPW 0.038–349 1400–190,000 –– – 1.0–47 Water use criteria Irrigation 1050 1 10 2 960 SDW 230 10 0.025 c d e f g Toxicity values LC50 2.7 (15 d Dm)7341(96hPp)315(96hPp)1341(96hPp ) 100(96hPp ) COCs* No No No No No No HFWE hydraulic fracturing well effluent, PW wastewater from pit, SGPW shale gas produced water, TGSPW tight gas sand produced water, CBMPW coalbed methane produced water, NGPW conventional natural gas produced water, ND not detected, – not determined, *COCs are defined as constit- uents in water extracts of drilling waste that have concentrations in excess of the use guidelines, Dm Daphnia magna, Pp Pimephales promelas a b c d e f Thacker et al. (2015). Alley et al. (2011). Canton and Wegman (1983). Mount et al. (1997). Smith et al. (1985). Scott and Crunkilton (2000). Ewell et al. (1986) oxidizable (metals bound to organic matter, medium mobili- the organic fraction. Stuckman et al. (2016)also stated that ty), and residual (metals strongly bound to the solid phase). metals present in drilling cuttings such as Cu, Ni, Zn, Cd, and According to research conducted by Kujawska and Cel Co were mainly associated with oxidizable phases. It can be (2017), heavy metals in drill cuttings were mainly bound to stated that these metals present in drill cuttings are Table 6 Minerals in drilling waste samples Minerals Drilling fluid solids (%) Drill cuttings (%) Drill cuttings (%) Drilling fluid dried powder solids (%) Wilke et al. (2015) Sawaengpol and Wannakomol (2017) Silurian and Ordovician Upper Cambrian Alum Lower Jurassic Posidonia Thailand shale, Poland shale, Denmark shale, Germany Quartz 24.6 29.2 – 8.9–25.6 43.83 Barite 10.4 13.3 – 5.1 1.39 Calcite 35.8 43.6 –– 14.21 Dolomite 2.8 3.4 –– – Sylvite 11.0 –– – – ) ) Muscovite-2M1 12.7 10.1 41.1–43.7* 7.0–25.5* – Orthoclase 2.7 – 6.3 –– Barium chloride – 0.5 –– – ) ) Carbonate 38.6** 47.0** – 30.3–73.4 – Kaolinite –– – 2.8–30.3 32.82 Pyrite –– 10.7–11.4 2.5–8.7 – Jarosite –– 4.2 –– Sanidine –– 8.9 –– Albite –– – 4–5.4 7.74 *Muscovite/illite, **Carbonate (calcite+dolomite) Environ Sci Pollut Res Fig. 3 An anionic chromatogram of the water extract of drilling fluid (DF5) characterized by medium mobility. Moreover, drill cuttings are rich in calcium, magnesium, and potassium which are different- made of ground rock while drilling fluids contain mainly water ly required by different species of plants and animals in the soil elements that could be extracted from rock or soil during drilling and water environment. Similar results were obtained in the operations and substances that were added to compose their research conducted on both the oil-based and water-based dril- formulations. Figure 2 shows metal contents in drill cuttings ling wastes from Nigerian wells (Gbadebo et al. 2010). from five different drilling locations. Taking into account, the Following the chemical characterization of the drilling Council Directive 86/278/EEC for heavy metal maximum per- fluids and drill cuttings, the main contaminants were found missible limits for soils, the studied drill cuttings samples did not to be Ba, Ni, Mn, Cu, Cr, Pb, arsenic (As), and Hg. exceed these limits. One of the drill cuttings sample (C2) exceeded the maximum permissible limit for Pb content recom- mended by the Regulation of the Minister of Environment Ion chromatography (IC) (Poland) (2016), for safety of the I class of soil. Mostavi et al. (2015) compared the results of drill cuttings chemical analysis Figures 3 and 4 show chromatograms of water extracts of dril- with the Toxicity Characteristic Leaching Procedure regulatory ling fluid and drill cuttings. Among determined ions, only chlo- levels and stated that examined drill cuttings can be classified as ride (R = 2.9 ± 0.1 min) and sulphate (Rt = 3.69 ± 0.1 min) were non-hazardous waste. identified. In an anionic chromatogram of water extracts of dril- Despite the fact that the total Ba levels in studied samples ling waste, carbonate peaks were identified (R =3.18± −1 were high (6.6–83.6 and 8.6–81.4 g kg 0.1 min). In the chromatogram of water extracts of drilling fluid for drilling fluids and drill cuttings, respectively), this element existed mainly in the is an unidentified peak with a retention time of 6.6 min. Quantity BaSO form which is a water and acid insoluble, and in this analysis showed that water extracts of drilling fluid contained −1 −1 form, the barium compound does not pose a threat to the envi- 24.4 mg kg of chlorideand0.87mgkg of sulphate. Water −1 ronment. For comparison, the maximum permissible limits for extracts of drill cuttings contained 5.7 mg kg of chloride and −1 − − 3− − heavy metal levels in soils according to Polish law are presented 6.37 mg kg of sulphate. F ,Br ,PO ,and NO ions were 4 3 (Table 2). It has been observed that drilling wastes are relatively not identified in studied water extract samples of drilling waste. Fig. 4 An anionic chromatogram of the water extracts of drill cuttings (C5) Environ Sci Pollut Res Fig. 5 XRD pattern of drilling fluid solids (DF5) dried at 50 °C The values of anion concentrations both in the water ex- had no COCs based on FAO irrigation guidelines, the USEPA tracts of drilling fluid solids and drill cuttings are lower than WQC and toxicity values (Table 5). those reported by other researchers (Alley et al. 2011; Thacker et al. 2015; Canton and Wegman 1983; Ewell et al. 1986; XRD analysis Mount et al. 1997; Scott and Crunkilton 2000; Smith et al. 1985) for other types of produced water. Beneficial use criteria XRD analysis was used to identify crystalline compounds − − − − were compared to anion concentrations (Br ,Cl ,F ,NO , (mineral) based on their crystal structure. Each compound 3− 2− PO ,SO ) to discern COCs present in water extracts of gives a unique pattern of diffraction peaks. Both drilling fluid 4 3 drilling fluid solids and water extracts of drill cuttings. It was solids and drill cuttings are characterized by very complex stated that these water extracts, according to anions presence, phase compositions. Rietveld’s analysis showed a very good Fig. 6 XRD pattern of cuttings sample (C5) dried at 105 °C Environ Sci Pollut Res fitting of a model and an experimental diffraction pattern. A of high levels of these elements that are toxic for humans, ani- result of the study is quality and semi-quantity analysis of mals, and the environment. The heavy metal contents in the drill compounds occurring in a crystalline form which are summed cuttings samples did not exceed the maximum permissible limits up to 100%. Phases of amorphous, organic, and other com- recommended by the EC regulation for safety of soils. The pounds that are present in trace amounts in the samples are not results showed the trend of higher metal contents (Mg, Cu, Fe, taken into consideration in the balance, which means that the Mn, Zn, Al, Cr, Pb, Ni) in the drill cuttings compared to drilling real element contents in studied samples are slightly lower. X- fluid samples. Analysis of the mineralogical character of a so- ray powder diffraction patterns of drilling waste are shown in lidified drilling fluid revealed that it contained calcite, quartz Figs. 5 and 6. muscovite, sylvite, barite, dolomite, and orthoclase and of drill Analysis of the mineralogical character of drilling fluid solids cuttings revealed that they contained calcite quartz, muscovite, (DF5) revealed that they contained 35.8% of calcite (CaCO ), barite, dolomite, and barium chloride. Taking the above results 24.6% of quartz (SiO ), 12.7% of muscovite 2M1 into account, the proper waste management, disposal, and reuse (KAl Si O (OH) ), 11.0% of sylvite, 10.4% of barite of drilling waste are vital to environment protection. The solid 2.9 3.1 10 2 (BaSO ), 2.8% of dolomite (CaMg(CO ) ), and 2.7% of ortho- wastes (drilling fluids and cuttings) if properly treated can serve 4 3 2 clase (KAlSi O ). XRD analysis of mineral compositions of dril- as raw materials for a soil amendment production. Such a soil 3 8 ling fluid dried powder samples collected from a petroleum drill amendment can be used for land reclamation of well sites, hard hole in northern Thailand showed that they contained 42.83% of rock mining sites, abandoned coal mines, refining and smelting quartz, 32.82% of kaolinite, 14.21 of calcite, 7.74% of albite, and sites, construction sites, and other contaminated sites. 1.39% of barite (Sawaengpol and Wannakomol 2017). Revitalization of these sites can be improved when soil amend- Analysis of the mineralogical character of drill cuttings ments are used. (C5) revealed that they contained 43.5% of calcite (CaCO ), Funding information This material is based upon work supported by the 29.2% of quartz (SiO ), 10.1% of muscovite 2M1 National Centre for Research and Development of Poland under Grant (KAl Si O (OH) ), 13.3% of barite (BaSO ), 3.4% of do- 2.9 3.1 10 2 4 No. BG1/SOIL/2013. lomite (CaMg(CO ) ), and 0.5% of barium chloride (BaCl ). 3 2 2 Open Access This article is distributed under the terms of the Creative XRD analysis of drill cuttings from other shales in Poland Commons Attribution 4.0 International License (http:// (Baltic Basin) showed that the major components of these creativecommons.org/licenses/by/4.0/), which permits unrestricted use, materials are quartz, sodium aluminum dioxide (NaAlO ), distribution, and reproduction in any medium, provided you give appro- aluminum silicate hydrate (Al O ·2SiO ·2H O, mineral kao- 2 3 2 2 priate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. linite), and wustite (FeO) (Mykowska et al. 2015). Wilke et al. (2015) determined the mineral content in black shales in Germany and Dernmark. XRD analysis revealed that shales from the Upper Cumbrian Age contained muscovite/illite, py- rite, sanidine, orthoclase, and jarosite whereas shales from References Lower Jurassic Age contained carbonate, muscovite/illite, quartz, kaolinite, albite, barite, and pyrite (Table 6). Adekomaya SO (2014) Development of approximate waste management strategies for drilling waste-Niger Delta (Nigeria) experience. J Environ Earth Sci 4(7):31–33 Adekunle IM, Igbuku AOO, Oguns O, Shekwolo PD (2013) Emerging Conclusions trend in natural resource utilization for bioremediation of oil — based drilling wastes in Nigeria, biodegradation - engineering and technology, Dr. Chamy (Ed.), InTech. doi: https://doi.org/10.5772/ Chemical characterization of the studied drilling waste showed 56526. 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Environmental Science and Pollution Research – Springer Journals
Published: May 28, 2018
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