吳 娜,聶志強(qiáng),李開環(huán),孫英杰,蔡洪英,張曼麗,周 瓊,黃啟飛

?

頁巖氣開采鉆井固體廢物的污染特性

吳 娜1,2,聶志強(qiáng)2*,李開環(huán)2,孫英杰1,蔡洪英3,張曼麗3,周 瓊3,黃啟飛2

(1.青島理工大學(xué)環(huán)境與市政工程學(xué)院,山東 青島 266033；2.中國環(huán)境科學(xué)研究院環(huán)境基準(zhǔn)與風(fēng)險(xiǎn)評(píng)估國家重點(diǎn)實(shí)驗(yàn)室/土壤與固體廢物環(huán)境研究所,北京 100012；3.重慶市固體廢物管理中心,重慶 401147)

選取重慶某地區(qū)3個(gè)頁巖氣田作為研究對(duì)象,研究了5個(gè)鉆井平臺(tái)頁巖氣開采過程中廢水基和油基鉆井巖屑中重金屬、多環(huán)芳烴(PAHs)和石油烴的污染特性.結(jié)果表明,兩類鉆井巖屑中Ba元素平均含量明顯高于其他重金屬,廢水基鉆井巖屑的重金屬以Zn、Ba、Cr、Ni、Cu、Pb為主,廢油基鉆井巖屑中的重金屬以Ni、Cu、Zn、Pb、Ba、As、Cr為主且Ni、Cu、Zn、Pb平均含量超過《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6-2007)標(biāo)準(zhǔn)限值.廢水基和油基鉆井巖屑中PAHs的范圍分別為1.74~14.8mg/kg和302~595mg/kg,均未超過GB5085.6-2007標(biāo)準(zhǔn)限值.廢油基鉆井巖屑石油烴含量為112~213g/kg,遠(yuǎn)超GB5085.6-2007標(biāo)準(zhǔn)限值.同時(shí),廢水基和油基鉆井巖屑中BaP超過《土壤環(huán)境質(zhì)量農(nóng)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB15618-2018)標(biāo)準(zhǔn)限值;廢油基鉆井巖屑中部分PAHs(BaP、BbF、BkF、DahA)濃度超過《土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB36600-2018)中篩選值,巖屑中石油烴含量遠(yuǎn)超管制值.

頁巖氣；固體廢物；重金屬；PAHs；石油烴；污染特性

重慶地區(qū)頁巖氣資源豐富,可開采儲(chǔ)量約2.05萬億方[1],而頁巖氣在勘探開發(fā)過程中會(huì)產(chǎn)生大量的固體廢物.據(jù)測(cè)算,典型單井清水鉆、水基鉆井共產(chǎn)生普通巖屑量約為1085m3,產(chǎn)生油基巖屑約為215m3,產(chǎn)生廢鉆井泥漿和污泥約為48.1m3.截至目前,重慶某地區(qū)的頁巖氣田累計(jì)產(chǎn)生鉆井固體廢物已超過43萬m3[2],這些固體廢物主要來自于鉆井過程中的廢棄泥漿及巖屑,含有無機(jī)鹽、有機(jī)化合物、重金屬離子及石油烴類等污染物.國內(nèi)外鉆井巖屑處理處置方法主要有直接排放法、固化處理法、土地耕作法、焚燒處理法、熱解法、萃取技術(shù)、密封填埋法和化學(xué)清洗法等.目前,大多研究以油氣田開采產(chǎn)生的固體廢物污染特性為主[3-6].例如,研究發(fā)現(xiàn)油氣田鉆井過程中產(chǎn)生的固體廢物主要包括廢氣泥漿、鉆井巖屑和生活垃圾,污染物主要有石油類、COD及部分重金屬[3];張鮮等[4]研究了某大型氣田固體廢物對(duì)環(huán)境的影響,發(fā)現(xiàn)其中含有的石油類、揮發(fā)酚、有機(jī)物、重金屬、鹽離子和堿性物等污染物對(duì)人體和環(huán)境有不同程度的損害.然而,目前針對(duì)頁巖氣開采鉆井固體廢物污染特性的研究較少,有研究發(fā)現(xiàn)有機(jī)物、重金屬和堿性物質(zhì)是油基鉆屑中的三類毒性物質(zhì),其中重金屬以Zn、As、Hg、Cd四種元素為主[7].由于頁巖氣屬于非常規(guī)天然氣,在開采過程所采用的工藝、固體廢物產(chǎn)生及污染特性、固體廢物處理處置方法均較常規(guī)油氣田的開采有所不同.因此,為控制頁巖氣開采固體廢物對(duì)環(huán)境和人類健康所產(chǎn)生的影響[8-9],對(duì)頁巖氣開采固體廢物污染特性的研究亟待開展.

本研究選取具有代表性的重慶市某地區(qū)的3個(gè)頁巖氣田作為研究對(duì)象,采集5個(gè)鉆井平臺(tái)鉆井階段產(chǎn)生的廢水基鉆井巖屑、廢油基鉆井巖屑樣品,對(duì)其中重金屬、PAHs、石油烴含量進(jìn)行了分析測(cè)定,明確固體廢物的污染特性,以期為頁巖氣開采的污染控制提供基礎(chǔ)數(shù)據(jù).

1 材料與方法

1.1 樣品采集

本研究的廢鉆井巖屑來源于重慶某地區(qū)頁巖氣開采所產(chǎn)生,頁巖氣鉆井階段采用三開鉆井方式,分別采集了A、B、C、D、E 5個(gè)平臺(tái)的廢鉆井巖屑,各鉆井平臺(tái)為不同位置的鉆井巖屑綜合處置場(chǎng).其中在D、E鉆井平臺(tái)采集廢水基鉆井巖屑,廢水基鉆井巖屑產(chǎn)生于鉆井平臺(tái)的二開斜井段,采用水基鉆井液鉆井工藝;在A、B、C和E鉆井平臺(tái)采集廢油基鉆井巖屑,廢油基鉆井巖屑產(chǎn)生于鉆井平臺(tái)的三開水平井段,采用油基鉆井液鉆井工藝.廢水基和油基鉆井巖屑樣品按照《工業(yè)固體廢物采樣制樣技術(shù)規(guī)范》(HJ/T20-1998)[10]進(jìn)行采集,其中廢水基鉆井巖屑采集泥漿池、固相控制設(shè)備篩下巖屑,巖屑呈暗灰色,泥狀固液混合物;廢油基鉆井巖屑采集振動(dòng)篩和集中貯存池中巖屑,巖屑為黑色黏稠狀.采集后的樣品均置于潔凈廣口棕色旋蓋玻璃瓶中,運(yùn)回實(shí)驗(yàn)室后于4℃冷藏保存.

1.2 樣品的測(cè)定

1.2.1 重金屬含量測(cè)定 依據(jù)《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)浸出毒性鑒別》(GB5085.3-2007)[11](附錄A 固體廢物元素的測(cè)定電感耦合等離子體原子發(fā)射光譜法)測(cè)定樣品中各種重金屬的含量.首先,稱取0.2g樣品放入25mL聚四氟乙烯消解罐中,加入2mL鹽酸、8mL硝酸、2mL氫氟酸和2mL雙氧水,蓋上聚四氟乙烯蓋,放置電熱板上175℃加熱(在對(duì)廢油基鉆井巖屑進(jìn)行消解時(shí)可適當(dāng)添加雙氧水,有研究表明雙氧水可以破壞廢油基鉆井巖屑中的有機(jī)物和聚合物,提高消解效果[12]).消解完成后冷卻至室溫,然后將消解罐放置150℃電熱板上加熱趕酸,至內(nèi)溶物近干.最后冷卻至室溫,用去離子水溶解內(nèi)溶物,將溶液定容至50mL.消解液采用電感耦合等離子體質(zhì)譜儀(賽默飛ICAP7200DUO),測(cè)試重金屬Cu、Zn、Cr、Pb、Cd、Be、Ba、Ni、Ag、Se、Hg、V、Mn、Co、Sb、Tl、As的含量.

1.2.3 石油類測(cè)定 石油類的測(cè)定參照《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6-2007)[14](附錄O 固體廢物可回收石油烴總量的測(cè)定紅外光譜法)用傅里葉變換紅外光譜儀(天津港東FTIR- 650)進(jìn)行測(cè)定.

1.3 質(zhì)量控制

實(shí)驗(yàn)過程中的質(zhì)量控制/質(zhì)量保證(QA/QC)參照GB5085.3-2007和HJ784-2016方法,包括平行樣測(cè)定、加標(biāo)回收率測(cè)定等,同時(shí)每隔5個(gè)樣品,進(jìn)溶劑空白、標(biāo)準(zhǔn)溶液以及過程空白.重金屬檢出限范圍為0.12~0.48μg/L,平均加標(biāo)回收率范圍為90%~ 105%;PAHs檢出限范圍為0.001~0.006μg/L,平均加標(biāo)回收率范圍為81%~101%.

2 結(jié)果與討論

2.1 重金屬污染特征

2.1.1 廢水基鉆井巖屑重金屬污染特性 D、E鉆井平臺(tái)廢水基鉆井巖屑中的重金屬平均含量測(cè)定結(jié)果如圖1所示,所測(cè)重金屬平均含量均未超過《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6- 2007)[14]標(biāo)準(zhǔn)限值,同時(shí)未超過《土壤環(huán)境質(zhì)量農(nóng)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB15618- 2018)[15]和《土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB36600-2018)[16]中規(guī)定含量.但Zn、Ba、Cr的平均含量相對(duì)較高,為廢水基鉆井巖屑中的主要重金屬污染物,Ni、Cu、Pb的平均含量相對(duì)較少,其他重金屬均未檢出.D平臺(tái)廢水基鉆井巖屑中Cr、Ni、Cu、Zn含量小于E平臺(tái),但Pb、Ba的含量大于E平臺(tái).原因可能是D平臺(tái)廢水基鉆井巖屑采集于固控設(shè)備篩下巖屑,未濃縮;E平臺(tái)采集于泥漿池內(nèi),由于蒸發(fā)濃縮可能導(dǎo)致濃度變高,同時(shí),由于地層影響,部分重金屬可能來源于地層.D和E平臺(tái)廢水基鉆井巖屑中Ba元素平均含量明顯高于其他重金屬,最高含量分別為4668mg/kg和3654mg/kg,原因可能是鉆井過程中為增加鉆井泥漿密度,通常加入加重材料重晶石(主要成分BaSO4),而典型工業(yè)重晶石大約包含53%Ba元素所致[17].吳明霞[18]對(duì)水基鉆井液的組分和毒性進(jìn)行了研究,發(fā)現(xiàn)水基鉆井液的大部分組分無毒難降解,但是其中重晶石粉、氫氧化鉀及氧化鈣具有化學(xué)毒性.

頁巖氣屬于非常規(guī)油氣,開采過程以及工藝與石油天然氣具有一定差異.D和E鉆井平臺(tái)廢水基鉆井巖屑重金屬平均含量與部分地區(qū)石油天然氣開采過程中廢水基鉆井巖屑具有一定差異.塔里木油田塔北地區(qū)廢水基鉆井巖屑中Cr、Ni、Cu、Zn、Pb元素與D和E鉆井平臺(tái)含量相當(dāng),同時(shí)檢測(cè)出As[19].而D和E鉆井平臺(tái)廢水基鉆井巖屑Cr、Ni、Cu、Zn、Pb、Ba、As元素平均含量均低于四川大巴山某氣田和AlaskanArctic地區(qū)鉆井所產(chǎn)生的水基鉆井泥漿[20-21].

圖1 廢水基鉆井巖屑重金屬含量Fig.1 Wastewater-based drilling cuttings heavy metal content

2.1.2 廢油基鉆井巖屑重金屬污染特性 廢油基鉆井巖屑主要以巖屑為主,同時(shí)含有少量的油基鉆井液,重金屬主要來源于油基鉆井液和井下地層,圖2顯示各平臺(tái)廢油基鉆井巖屑不同重金屬含量.根據(jù)《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6-2007)[14],所測(cè)的重金屬中Ni、Cu、Zn、Pb 4種重金屬平均含量超過標(biāo)準(zhǔn)限值,Ba的平均含量較高但沒有超過標(biāo)準(zhǔn)限值,Cr、As的平均含量相對(duì)較低,其它重金屬元素均未檢出.A平臺(tái)Cr、Ni、Cu、Zn、Pb、Ba元素平均含量較其他平臺(tái)均為最高,分別為42.0,56.7,35.4,186,83.2,2292mg/kg,不同平臺(tái)之間Cr、Ni、Cu、As的差異較小,Zn、Pb、Ba差異較大.Ba的平均含量差異較大,主要可能是由于不同鉆井深度具有不同的地層壓力,根據(jù)地層壓力鉆井液中加入不同量的重晶石粉來穩(wěn)定和調(diào)節(jié)鉆井液密度.先前的研究表明鉆井液所添加的添加劑,一般會(huì)導(dǎo)致鉆井液中Zn、Pb等金屬元素含量的增加[22],因此Zn、Pb差異較大主要來源于不同鉆井條件下添加劑影響.同一平臺(tái)鉆井巖屑不同重金屬含量差異也較大,整體而言,Ba元素平均含量最大,其次是Zn元素, Cr、Ni、Cu含量相當(dāng).根據(jù)上述分析,Zn、Pb、Ba主要受到添加劑影響,Cr、Ni、Cu、As主要來源于深井地層.

圖2 廢油基鉆井巖屑不同重金屬含量Fig.2 Waste oil-based drilling cuttings with different heavy metal content

由于頁巖氣開采工藝特殊,以及地層環(huán)境的不同,本研究的廢油基鉆井巖屑重金屬平均含量與其他油氣田開采地區(qū)差異較大,Cr、Ni、Cu、Zn、As、Pb平均含量均明顯高于西南某頁巖氣廢油基鉆井巖屑中含量(2.41,2.46,1.19,5.92,0.53,2.12mg/kg)[23],但均未超過《土壤環(huán)境質(zhì)量農(nóng)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB15618-2018)[15]和《土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB36600-2018)[16]中規(guī)定濃度.

2.2 PAHs污染特征

2.2.1 廢水基鉆井巖屑PAHs污染特性 廢水基鉆井巖屑主要以巖屑、水、黏土(主要用膨潤土)、以及各種有機(jī)和無機(jī)材料組成,廢水基鉆井巖屑中的PAHs主要來源于添加劑,包括潤滑劑、降濾失劑等.如圖3所示,E鉆井平臺(tái)的廢水基鉆井巖屑∑PAHs濃度明顯高于D平臺(tái),分別為14.8和1.74mg/kg.E平臺(tái)廢水基鉆井巖屑采集于泥漿池內(nèi),泥漿池內(nèi)廢水基鉆井巖屑經(jīng)過加藥、絮凝、沉淀、濃縮,上清液回收利用配置水基鉆井液,在整個(gè)鉆井階段泥漿池內(nèi)的廢水基鉆井巖屑不斷進(jìn)行濃縮,D平臺(tái)廢水基鉆井巖屑采集于固控設(shè)備篩下巖屑,尚未經(jīng)歷過濃縮,因此導(dǎo)致E鉆井平臺(tái)的廢水基鉆井巖屑中∑PAHs濃度明顯高于D鉆井平臺(tái).廢水基鉆井巖屑中∑PAHs含量均未超過《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6- 2007)[14]標(biāo)準(zhǔn)限值.

D和E鉆井平臺(tái)的廢水基鉆井巖屑中不同環(huán)數(shù)的PAHs的組成結(jié)構(gòu)相似,均以4環(huán)PAHs為主,所占百分比分別為41.9%和46.8%,2~3環(huán)PAHs濃度最低,所占百分比分別為22.1%和22.2%,5~6環(huán)PAHs所占百分比分別為36.0%和31.0%.這與潘峰等[24]研究結(jié)果相似,可能與小分子PAHs容易通過揮發(fā)和淋溶作用遷移,而高環(huán)數(shù)的PAHs不易降解有關(guān).

圖3 D、E鉆井平臺(tái)廢水基鉆井巖屑∑PAHs及2~3環(huán)、4環(huán)、5~6環(huán)PAHs濃度Fig.3 D, E drilling platform wastewater based drilling debris ∑ PAHs and 2~3 ring, 4 ring, 5~6 ring PAHs concentration

D、E鉆井平臺(tái)廢水基鉆井巖屑中16種PAHs濃度分布如圖4所示.D鉆井平臺(tái)Fla含量為最高,約占總量的18%,其次,Phe、Pyr、BbF含量也較高,為巖屑中主要污染物.而E平臺(tái)Pyr含量最高,約占總量的17%,其次是Phe.其中E鉆井平臺(tái)中BaP濃度超過《土壤環(huán)境質(zhì)量農(nóng)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB15618-2018)[15]中規(guī)定的0.55mg/kg,但兩平臺(tái)∑PAHs濃度均未超過《土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB36600- 2018)[16]中第二類用地的篩選值.

2.2.2 廢油基鉆井巖屑PAHs污染特性 A、B、C、E鉆井平臺(tái)內(nèi)廢油基鉆井巖屑中的∑PAHs及2~3環(huán)、4環(huán)、5~6環(huán)PAHs濃度如圖5所示,不同鉆井平臺(tái)之間∑PAHs濃度差異較大,從高到低為C平臺(tái)>B平臺(tái)>A平臺(tái)>E平臺(tái).C平臺(tái)濃度最高,為595mg/kg,高于原油儲(chǔ)罐底泥中∑PAHs的濃度550mg/kg[25], E平臺(tái)濃度最低,為302mg/kg.A、B、C三個(gè)平臺(tái)廢油基鉆井巖屑中∑PAHs濃度均低于中原油田原始油泥和干油泥中含量(1953~4112mg/ kg)[26].廢油基鉆井巖屑中∑PAHs含量均未超過《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6- 2007)[14]標(biāo)準(zhǔn)限值.

圖4 D、E鉆井平臺(tái)廢水基鉆井巖屑中PAHs各同系物濃度分布Fig.4 Concentration distribution of PAHs in the cuttings of D and E drilling platforms

圖5 A、B、C、E鉆井平臺(tái)廢油基鉆井巖屑∑PAHs及2~3環(huán)、4環(huán)、5~6環(huán)PAHs濃度Fig.5 A, B, C, E drilling platform waste oil-based drilling debris ∑ PAHs and 2~3 ring, 4 ring, 5~6 ring PAHs concentration

不同環(huán)數(shù)的PAHs含量不同.A、B、E鉆井平臺(tái)廢油基鉆井巖屑都以4環(huán)PAHs為主,分別占∑PAHs的47.5%、57.2%、54.5%,其次是2~3環(huán)PAHs,分別占∑PAHs的40.7%、40.6%、39.8%,5~6環(huán)PAHs含量最少,E鉆井平臺(tái)僅為11.8%,A和B鉆井平臺(tái)所占比例均不到10%.而C鉆井平臺(tái)的廢油基鉆井巖屑中PAHs以5~6環(huán)為主(74.5%),4環(huán)PAHs含量最少(11.0%).

相關(guān)研究發(fā)現(xiàn)PAHs來源分為熱轉(zhuǎn)化和成巖作用.熱轉(zhuǎn)化是化石、非化石燃料在高溫厭氧環(huán)境下生成,而成巖作用則主要來自原油形成過程[27].研究發(fā)現(xiàn)高環(huán)(4環(huán)及5~6環(huán))的PAHs主要來源于熱轉(zhuǎn)化過程,低環(huán)(2~3環(huán))PAHs則主要來源于成巖作用[28-29].通常利用低環(huán)(LMW)/高環(huán)(HMW)比例來判斷來源,當(dāng)LMW/HMW<1時(shí),說明PAHs來源于熱轉(zhuǎn)化,反之則來源于成巖作用[30].本次研究中A、B、C、E鉆井平臺(tái)廢油基鉆井巖屑LMW/HMW比值分別為0.687、0.682、0.660、0.124,均小于1,而且在深井地層由于地?zé)岷湍Σ恋淖饔?導(dǎo)致油基鉆井液溫度較高,具備熱轉(zhuǎn)化的條件,所以PAHs主要來源于熱轉(zhuǎn)化.

如圖6所示,A、B、E鉆井平臺(tái)廢油基鉆井巖屑中Fla濃度最大,其次是Phe,為巖屑中的主要污染物,而C鉆井平臺(tái)廢油基鉆井巖屑中BkF濃度最大,占到PAHs總量的69.3%.4個(gè)平臺(tái)的BaP濃度均超過《土壤環(huán)境質(zhì)量農(nóng)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB15618-2018)[15]中規(guī)定的0.55mg/kg,同時(shí)四個(gè)平臺(tái)的BaP,C平臺(tái)的BbF、BkF和E平臺(tái)的BbF、DahA濃度也超過《土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB36600-2018)[16]中第二類用地的篩選值,但都未超過管制值.

圖6 A、B、C、E鉆井平臺(tái)廢油基鉆井巖屑中PAHs各同系物濃度分布 Fig.6 Concentration distribution of PAHs in the cuttings of waste oil-based drilling in A, B, C and E drilling platforms

2.3 石油烴污染特征

含油污泥是油田開發(fā)過程中產(chǎn)生的主要污染源,被《國家危險(xiǎn)廢物名錄》(2016)[31]列為危險(xiǎn)廢物進(jìn)行管理.含油污泥來源于罐底泥、浮渣和落地原油等[32],其石油烴含量一般在10%(干重)以上,部分高達(dá)20%~ 30%,因此石油烴是含油污泥中的主要污染物.

黃曉英等[33]采用四氯化碳對(duì)含油污泥進(jìn)行振蕩提取120min,用紅外分光光度法測(cè)定石油烴含量,含量為0.074~14.6g/kg.王小雨等[34]對(duì)莫莫格濕地油田進(jìn)行開采,油田開采20年時(shí)周圍土壤中石油烴含量最高可達(dá)50g/kg.美國得克薩斯州把石油烴濃度10g/kg作為油田開采區(qū)污染管理標(biāo)準(zhǔn)[35].本次研究中頁巖氣開采產(chǎn)生的廢油基鉆井巖屑石油烴含量為112~213g/kg,遠(yuǎn)遠(yuǎn)超過《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別》(GB5085.6-2007)[14]標(biāo)準(zhǔn)限值和《土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行)》(GB36600-2018)[16]中規(guī)定的9g/kg,濃度最大的為B平臺(tái)廢油基鉆井巖屑,濃度最低的為A平臺(tái).

廢油基鉆井巖屑石油烴的含量與鉆井過程中油基鉆井液的使用量有關(guān),由不同的地層環(huán)境和鉆井深度決定,同時(shí)還與鉆井平臺(tái)的廢油基鉆井巖屑固液分離裝置分離效果有關(guān),不同的分離裝置,在進(jìn)行固液分離時(shí)分離效果也不同,導(dǎo)致石油烴含量差距也較大.本研究平臺(tái)在進(jìn)行廢油基鉆井巖屑處理前需要對(duì)暫存池內(nèi)的鉆井巖屑進(jìn)行調(diào)和,包括固液比,石油烴含量等,以保證設(shè)備的最佳運(yùn)行狀態(tài),所以通常還會(huì)添加一部分分離出的鉆井液,控制廢油基鉆井巖屑的粘稠度、固液比等.因此B和C平臺(tái)內(nèi)的廢油基鉆井巖屑很有可能已經(jīng)添加部分分離出的鉆井液,導(dǎo)致石油烴含量較高.

3 結(jié)論

3.1 廢水基鉆井巖屑中Zn、Ba、Cr的平均含量相對(duì)較高,廢油基鉆井巖屑中Ba元素平均含量明顯高于其他重金屬,且A鉆井平臺(tái)Cr、Ni、Cu、Zn、Pb、Ba元素平均含量較其他平臺(tái)均為最高.

3.2 廢水基鉆井巖屑中PAHs的組成均以4環(huán)為主,PAHs濃度范圍為1.74~14.8mg/kg ,E鉆井平臺(tái)的PAHs濃度明顯高于D平臺(tái).廢油基鉆井巖屑中A、B、E鉆井平臺(tái)都以4環(huán)PAHs為主,C鉆井平臺(tái)以5~6環(huán)為主,PAHs濃度從高到低為C平臺(tái)>B平臺(tái)>A平臺(tái)>E平臺(tái),濃度范圍為302~595mg/kg.

3.3 廢油基鉆井巖屑石油烴含量范圍為112~ 213g/kg,其中B鉆井平臺(tái)廢油基鉆井巖屑濃度最大,A鉆井平臺(tái)濃度最低.

[1] 閆力源,盧培利,張 虹,等.重慶頁巖氣資源潛在開發(fā)區(qū)生態(tài)環(huán)境特征分析及相關(guān)保護(hù)建議 [C]//中國環(huán)境科學(xué)學(xué)會(huì)年會(huì)論文集.深圳:中國環(huán)境科學(xué)學(xué)會(huì), 2015:5518-5522.Yan Li-yuan, Lu Pei-li, Zhang Hong, et al. Chongqing shale gas resource potential development zone ecological environment characteristics and related protection suggestions [C]//China Environmental Science Association Annual Meeting. Shenzhen: Chinese Society or Environmental Sciences, 2015:5518-5522.

[2] 許 坤,李 豐,姚 超,等.我國頁巖氣開發(fā)示范區(qū)進(jìn)展與啟示 [J]. 石油科技論壇, 2016,(1):44-49.Xu Kun, Li Feng, Yao Chao, et al. Progress and enlightenment of China's shale gas demonstration zone [J]. Petroleum Science and Technology Forum. 2016,(1):44-49.

[3] 朱 維.油氣田勘探開發(fā)污染及防治 [J]. 環(huán)境保護(hù)與治理, 2015, 15(12):31-33.Zhu Wei. Investigation and development pollution and prevention of oil and gas fields [J]. Environmental Protection and Remediation, 2015,15(12):31-33.

[4] 張 鮮,劉 丹,葉宣宏.淺析氣田開發(fā)鉆井固體廢物對(duì)環(huán)境的影響及處置措施 [J]. 四川環(huán)境, 2011,30(4):88-91.Zhang Xian, Liu Dan, Ye Xuan-hong. Effect of solid waste and disposal of drilling in gasfield development on environment [J]. Sichuan Environment, 2011,30(4):88-91.

[5] 沈曉莉,楊金忠,徐天有,等.典型地區(qū)油氣田水基鉆井巖屑污染特征研究 [J]. 環(huán)境污染與防治, 2017,39(5):480-483.Shen Xiao-li, Yang Jin-zhong, Xu Tian-you, et al. Research on pollution characteristic of water-based drilling cuttings of typical oil-gas fields [J]. Environmental Pollution and Control, 2017,39(5): 480-483.

[6] 李 龍,沙依繞,陳 鵬.新疆油田稠油開發(fā)固體廢物對(duì)環(huán)境的影響及處置措施 [J]. 油氣田環(huán)境保護(hù), 2007,17(1):34-36. Li Long, Sha Yi-rao, Chen Peng. Environmental impacts of solid waste development in Xinjiang oilfield and its disposal measures [J]. Environmental Protection of Oil and Gas Fields, 2007,17(1):34-36.

[7] 陳則良.頁巖氣油基鉆屑的污染特性和蒸汽浸洗研究 [D]. 北京:中國科學(xué)院大學(xué), 2017. Chen Ze-liang. Study on pollution characteristics and pressurized hot water extraction of shale gas oil-based drill cuttings [D]. Beijing: University of Chinese Academy of Sciences, 2017.

[8] Centner T J, Petetin L. Permitting program with best management practices for shale gas wells to safeguard public health [J]. Journal of Environmental Management, 2015,163:174-183.

[9] Soeder D J, Sharma S, Pekney N, et al. An approach for assessing engineering risk from shale gas wells in the United States [J]. International Journal of Coal Geology, 2014,126:4-19.

[10] HJ/T20-1998 工業(yè)固體廢物采樣制樣技術(shù)規(guī)范 [S]. HJ/T20-1998 Technical specifications on sampling and sample preparation from industry solid waste [S].

[11] GB5085.3-2007 危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)浸出毒性鑒別 [S]. GB5085.3-2007 Identification standards for hazardous wastes- Identification for extraction toxicity [S].

[12] 黃 海,屈 展,周立輝,等.廢棄鉆井液重金屬檢測(cè)及其污染性評(píng)價(jià) [J]. 陜西師范大學(xué)學(xué)報(bào)(自然科學(xué)版), 2012,40(5):52-55.Huang Hai, Qu Zhan, Zhou Li-hui, et al. Detection and evaluation of heavy metal in abandoned drilling fluid [J]. Journal of Shaanxi Normal University (Natural Science Edition), 2012,40(5):52-55.

[13] HJ784-2016 土壤和沉積物多環(huán)芳烴的測(cè)定高效液相色譜法 [S].HJ784-2016Soil and sediment-Determination of polycyclic aromatic hydrocarbons-High performance liquid chromatography [S].

[14] GB5085.6-2007 危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)毒性物質(zhì)含量鑒別 [S].GB5085.6-2007 Identification standards for hazardous wastes- Identification for toxic substance content [S].

[15] GB15618-2018土壤環(huán)境質(zhì)量農(nóng)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行) [S].GB15618-2018 Soil environmental quality risk control standard for soil contamination of agricultural land (Trial) [S].

[16] GB36600-2018 土壤環(huán)境質(zhì)量建設(shè)用地土壤污染風(fēng)險(xiǎn)管控標(biāo)準(zhǔn)(試行) [S].GB36600-2018 Soil environmental quality Risk control standard for soil contamination of development land (Trial) [S].

[17] Trefry J H, Trocine R P, McElvaine M L, et al. Total mercury and methylmercury in sediments near offshore drilling site-s in the Gulf of Mexico [J]. Environmental Geology, 2007,53(2):375-385.

[18] 吳明霞.廢棄水基鉆井液環(huán)境影響及固化處理技術(shù)研究 [D]. 大慶:東北石油大學(xué), 2012.Wu Ming-xia. Environmental Impact and Solidification of Water- based Drilling Fluid [D]. Daqing: Northeast Petroleum University, 2012.

[19] 杜春蕾.油田鉆井廢棄泥漿中重金屬分布特征與污染評(píng)價(jià)-以中石油塔里木分公司塔北井區(qū)為例[D]. 烏魯木齊:新疆大學(xué), 2015.Du Chun-lei. Research on distribution characteristics and pollution evaluation of heavy metals in abandoned drilling mud in oil field-case in Tabei Field of Tarim branch of Petro China [D]. Urumqi: Xinjiang University, 2015.

[20] Zhang A, Li M, Lv P, et al. Disposal and reuse of drilling solid waste from a massive gas field [J]. Procedia Environmental Sciences, 2016,31:577-581.

[21] Trefry J H, Dunton K H, Trocine R P, et al. Chemical and bi-ological assessment of two offshore drilling sites in the Al-askan Arctic [J]. Marine Environmental Research, 2013,86(3):35-45.

[22] 盧邦俊.頁巖氣鉆屑中的重金屬成分研究 [J].能源環(huán)境保護(hù), 2015, 29(6):20-60.Lu Bang-jun. Studies on the content of heavy metals in drilling chips from exploitation of shale gas [J]. Energy Conservation, 2015,29(6): 20-60.

[23] 孫根行,王麗芳,符 丹,等.廢棄油基鉆井巖屑焚燒處理基礎(chǔ) [J]. 鉆井液與完井液, 2017,34(3):59-65.Sun Gen-xing, Wang Li-fang, Fu Dan, et al. Burning of drill cuttings from wells drilled with waste oil base drilling fluid [J]. Drilling Fluid & Completion Fluid, 2017,34(3):59-65.

[24] 潘 峰,耿秋娟,楚紅杰,等.石油污染土壤中多環(huán)芳烴分析及生態(tài)風(fēng)險(xiǎn)評(píng)價(jià) [J]. 生態(tài)與農(nóng)村環(huán)境學(xué)報(bào), 2011,27(5):42-47. Pan Feng, Geng Qiu-juan, Chu Hong-jie, et al. Analysis of polycyclic aromatic hydrocarbons in petroleum contaminated soils and its ecological risk assessment [J]. Journal of Ecology and Rural Environment, 2011,27(5):42-47.

[25] Bojes H K, Pope P G. Characterization of EPA's 16priority pollutant polycyclic aromatic hydrocarbons (PAHs) in tank bottom solids and associated contaminated soils at oil exploration and production sites in Texas [J]. Regul Toxicol Pharmacol, 2007,47(3):288-295.

[26] 匡少平,孫東亞,孫玉煥,等.中原油田油泥及周邊土壤中PAHs的污染特征 [J]. 農(nóng)業(yè)環(huán)境科學(xué)學(xué)報(bào), 2008,27(3):855-861.Kuang Shao-ping, Sun Dong-ya, Sun Yu-huan, et al. Pollution characteristics of PAHs in oily sludge and around soils of Zhongyuan Oil Field [J]. Journal of Agro-Environment Science, 2008, 27(3):855-861.

[27] 何 燕.重慶市主城區(qū)水中多環(huán)芳烴的污染狀況分析及環(huán)境行為初步研究 [D]. 重慶:西南大學(xué), 2008. He Yan. Primary Study on polycyclic aromatic hydrocarbons in surface water of Chongqing District [D]. Chongqing: Southwest University, 2008.

[28] Mai B, Fu J, Sheng G, et al. Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments fro-m Pearl River Delta, China [J]. Environmental Pollution, 2002,117:457-474.

[29] Kucuksezgin F, Pazi I, Gonul L. Marine organic pollutants of the Eastern Aegean: aliphatic and polycyclic aromatic hydrocarbons in Candarli Gulf surficial sediments [J]. Marine Pollution Bulletin, 2012, 64:2569–2575.

[30] Kucuksezgin F, Pazi I, Gonul L. Marine organic pollutants of the Eastern Aegean: Aliphatic and polycyclic aromatic hydrocarbons in Candarli Gulf surficial sediments [J]. Marine Pollution Bulletin, 2012,64(11):2569-2575.

[31] 國家危險(xiǎn)廢物名錄(2016) [S]. National Hazardous Waste Directory (2016) [S].

[32] 王萬福,何銀花,劉 穎.含油污泥的熱解處理與利用 [J]. 油氣田環(huán)境保護(hù), 2006,16(2):15-18.Wang Wan-fu, He Yin-hua, Liu Ying. Pyrolysis treatment and utilization of oily sludge [J]. Environmental Protection of Oil and Gas Fields, 2006,16(2):15-18.

[33] 黃曉英,白鶴鳴,潘文啟.含油污泥石油類測(cè)定方法研究 [J]. 油氣田環(huán)境保護(hù), 2015,25(3):54-56. Huang Xiao-ying, Bai He-ming, Pan Wen-qi. Study on the determination method of petroleum sludge in oily sludge [J]. Environmental Protection of Oil & Gas Fields, 2015,25(3):54-56.

[34] 王小雨,馮 江,王 靜.莫莫格濕地油田開采區(qū)土壤石油烴污染及對(duì)土壤性質(zhì)的影響 [J]. 環(huán)境科學(xué), 2009,30(8):2394-2401.Wang Xiao-yu, Feng Jiang, Wang Jing. Petroleum hydrocarbon contamination and impact on soil characteristics from oilfield momoge wetland [J]. Chinese Journal of Environmental Science, 2009,30(8): 2394-2401.

[35] Railroad Commmission of Texas (RRC). Clean up of soil contaminated by a crude oil spill [R]. Austin: TX.

Pollution characteristics of solid waste in shale gas mining drilling.

WU Na1,2, NIE Zhi-qiang2*, LI Kai-huan2, SUN Ying-jie1, CAI Hong-ying3, ZHANG Man-li3, ZHOU Qiong3, HUANG Qi-fei2

(1.School of Environmental and Municipal Engineer, Qingdao University of Technology, Qingdao 266033, China；2.State Key Laboratory of Environmental Criteria and Risk Assessment, Soil and Solid Waste Environmental Research Institute, Chinese Research Academy of Environmental Sciences, Beijing 100012, China；3.Chongqing Solid Waste Management Center, Chongqing 401147, China)., 2019,39(3)：1094~1100

Three shale gas fields in ??Chongqing were selected. The pollution characteristics of heavy metals, polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbons in wastewater-based and waste oil-based drilling cuttings from the shale gas mining of five drilling platforms were studied. The concentration of Ba in wastewater-based and waste oil-based drilling cuttings was significantly higher than that of other heavy metals. Zn, Ba, Cr, Ni, Cu and Pb were the main heavy metals in the wastewater-based drilling cuttings. While Ni, Cu, Zn, Pb, Ba, As, Cr were the main heavy metals in the waste oil-based drilling cuttings and among which the concentration of Ni, Cu, Zn and Pb exceeded the corresponding limit. The concentration of PAHs in wastewater-based and waste oil-based drilling cuttings were 1.74~14.8mg/kg and 302~595mg/kg, respectively, which did not exceed the limit of the identification standards for hazardous wastes-identification for toxic substance content. The concentration of the petroleum hydrocarbon in waste oil-based drilling cuttings was 112~213g/kg, which was much higher than the limit of the identification standards for hazardous wastes-identification for toxic substance content. At the same time, the concentration of BaP in the wastewater-based and waste oil-based drilling cuttings was higher than the limit of the soil environmental quality-risk control standard for soil contamination of agricultural land; the concentration of BaP, BbF, BkF and DahA in the waste oil-based drilling cuttings were higher than the screening values of the soil environmental quality-risk control standard for soil contamination of development land and the concentration of the petroleum hydrocarbons in the drilling cuttings were much higher than the intervention values.

shale gas；solid waste；heavy metals；PAHs；petroleum hydrocarbons；pollution characteristics

X54

A

1000-6923(2019)03-1094-07

吳 娜(1995-),女,山東青島人,青島理工大學(xué)碩士研究生,主要從事固體廢物利用處置與風(fēng)險(xiǎn)控制研究方向.

2018-08-22

中央級(jí)公益性科研院所基本科研業(yè)務(wù)專項(xiàng)(2018YSKY-009);北京市自然科學(xué)基金資助項(xiàng)目(8172048)

* 責(zé)任作者, 副研究員, niezq@craes.org.cn