Rapid Lava Sand Filtration for Decentralized Produced Water Treatment System in Old Oil Well Wonocolo
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Vol. 5 No. 2 (May 2019) RESEARCH ARTICLE https://doi.org/10.22146/jcef.43760 Rapid Lava Sand Filtration for Decentralized Produced Water Treatment System in Old Oil Well Wonocolo Ekha Yogafanny1*, Ayu Utami1, Kristiati E.A.2, Wibiana W. Nandari3 1Department of Environmental Engineering, Universitas Pembangunan Nasional Veteran Yogyakarta, INDONESIA 2Department of Petroleum Engineering, Universitas Pembangunan Nasional Veteran Yogyakarta, INDONESIA 3Department of Chemical Engineering, Universitas Pembangunan Nasional Veteran Yogyakarta, INDONESIA *Corresponding author: [email protected] SUBMITTED 25 February 2019 REVISED 18 March 2019 ACCEPTED 25 April 2019 ABSTRACT The Cepu Block Oil Field has been traditionally extracted since 2008 by the local community in Wonocolo. The oil well-produced gas and fluids consisted of crude oil and produced water. This oil production activity discharges high amounts of produced water. The fluids have been settled down in the sedimentation tank to gain the crude oil optimally. The remaining fluid called produced water has been discharged to the surface towards the river without any further treatment. This activity led to the deterioration of environmental quality. This study aimed to analyze the performance of produced water treatment by rapid sand filtration by measuring the degree of turbidity removal under the specific condition on a laboratory scale using lava sand. The sedimentation was conducted in 3 hours of retention time following the real field condition of the oil production process by community in one sample well. The rapid sand filtration was conducted by a fixed bed column method with 0.2 cm of grain size. The sedimentation process followed by the rapid sand filtration in produced water treatment yielded the high efficiency of turbidity removal reaching 98.65 %. The rapid sand filter also worked excellently in turbidity removal attaining 96.48 % of efficiency. These results confirmed that the sedimentation already done by the community followed by the rapid sand filtration is promising decentralized technology to be applied in a remote area such as Old Oil Wells Wonocolo regarding turbidity removal. KEYWORDS Produced Water; Decentralized System; Rapid Sand Filtration © The Author(s) 2018. This article is distributed under a Creative Commons Attribution-ShareAlike 4.0 International license. 1 INTRODUCTION The complexity of produced water composition The Oil and Gas industry consists of two major depends on the geographic location of the oil field, sectors, i.e. upstream and downstream sector. The geological formation, and the extraction method. The upstream sector includes exploration and production/ produced water from natural gas production is ten exploitation/ extraction (Igunnu and Chen, 2012), times more toxic than that from the oil production, while the downstream sector involves refinery as well but the volume of produced water discharge from as storage, distribution/ transportation, and natural gas production is much lower (Jiménez et al., marketing of the products (Kristiati, 2010; Amponsah 2018). and Opei, 2014). The wastewater generated from oil production/ exploitation/ extraction activities (upstream sector) is called produced water that is differentiated by so-called wastewater associated with oil refinery activities in the downstream sector, as it is shown in Figure 1. Naturally, a certain amount of water sits in the porous reservoir media together (a) with hydrocarbon and gas. It is known as the formation of water. Produced water is categorized as a form of water which is trapped in the reservoir and other sources of water (additional water injection to maintain hydraulic pressure or enhanced oil recovery) extracted or pumped to the surface together with (b) crude oil during the oil and gas production activities Figure 1. (a) Produced water from upstream activities, (b) Wastewater from downstream activities (Jiménez et al., (Arthur, Langhus and Patel, 2005; Fakhru’l-Razi et al., 2018). 2009; Jiménez et al., 2018). 113 Vol. 5 No. 2 (May 2019) Journal of the Civil Engineering Forum The volume of produced water is relatively high for The history of the exploration of oil fields in more than 80% of liquid pumped to the surface in Indonesia has been started since 1879, when Dutch potential fields and as high as 95% in aging or old oil Company, Dordsche Petroleum Maatschappij (DPM) fields (Igunnu and Chen, 2012). The major group's discovered and exploited oil in Ledok Field in Cepu, constituents of produced water are as follows: Central Java (Kristiati, 2010). Once deemed a) Salts (expressed as salinity, total dissolved solid uneconomical, the oil field was abandoned, and since (TDS), or electrical conductivity) 2008 this aging/ old oil wells in The Cepu Block were b) Oil and Grease (O&G) extracted traditionally by the community in c) BTEX (benzene, toluene, ethylbenzene, and Wonocolo. Since the old oil wells were extracted xylenes) traditionally by local people, these activities have not d) PAHs (polyaromatic hydrocarbons) been equipped by produced water treatment process e) Organic acids The Cepu Block Oil Field Wonocolo is one of the well- f) Phenol known aging or old oil field in Indonesia. Jati (2013) g) Natural inorganic and organic compounds (e.g. found that oil production activities in Wonocolo had chemicals that cause hardness and scaling such as a negative impact on the environment (land and calcium, magnesium, sulfates, and barium) surface water) as shown in Figure 2. However, this h) The chemical additive used during the drilling activity has been providing job opportunity and process that may have toxic properties (Fakhru’l- income for local communities. Razi et al., 2009; Jiménez et al., 2018). (c) (a) (d) (b) (e) Figure 2. (a) Soil contamination in Oil Field Wonocolo, (b) Area of oil production, (c) sedimentation tank, (d) oil sludge deposition in the sedimentation tank, (e) produced water discharge to the environment after the sedimentation tank 114 Journal of the Civil Engineering Forum Vol. 5 No. 2 (May 2019) Recently, the produced water was discharged to the operational cost, and additional chemicals. The environment which then flowed to the small river treatment process of produced water differs by the crossed the oil field. The produced water from the intended disposal method of the treated water. The sample well has a high turbidity concentration, i.e. disposal methods of produced water are 105 NTU. Not only the turbidity concentration but environmental discharge, re-injection for pressure also the total dissolved solids (TDS) of produced water maintenance, and reuse for irrigation, livestock was high, i.e. >10.000 mg/l. Since the concentration of watering, aquifer storage, industrial process water these two parameters was higher than the Indonesia (Jiménez et al., 2018). The common treatment Regulation (PP RI No. 82 the Year 2001 on Water techniques are physical treatment (adsorption, Quality Management and Water Pollution Control), cyclones, enhanced floatation), biological treatment, the produced water needs to be treated before its membrane treatment (polymeric membranes, disposal. The treated water will be discharged to the inorganic membranes, microfiltration/ ultrafiltration, river that was usually used for aquaculture and nanofiltration and reverse osmosis), thermal agriculture. This river is a tributary of Bengawan Solo technologies (evaporation, multistage flash, multi- River. The intended water quality is reaching the effect distillation, etc), and chemical treatment (ion third class (for aquaculture) mentioned in PP RI No. exchange, advanced oxidation process, chemical 82 the Year 2001. In this class, the turbidity should be precipitation, etc). These kinds of technologies are less than 25 NTU and TDS less than 1000 mg/l. usually combined one to each other to reach the intended treated water quality and to sustain the In old oil wells Wonocolo, the sedimentation tank is equipment used in the treatment process (Jiménez et already installed near the oil well. This tank was built al., 2018). to allow the fluids extracted from the reservoir settling down for some hours (minimum 3 hours) to The wastewater treatment system consists of three gain the crude oil optimally by the oil-water basic components, i.e. wastewater collection, separation process. The crude oil that floats on the wastewater treatment, and treated wastewater surface is taken manually using a water dipper. The disposal. The first component is very important in remaining fluid, the produced water, is discharged centralized systems but costs more than 60% of the into the environment through the pipe from the total budget in the wastewater management system bottom of the tank. The illustration of the oil (Zaharia, 2017). Based on the geographical condition production process in old oil wells Wonocolo can be of old oil field Wonocolo, the lack of funding as well seen in Figure 3. as skill and knowledge, and indigenous local wisdom, it is worth to consider the decentralized produced water treatment in each oil well or adjacent oil wells. The decentralized system of produced water treatment allows the worker to individually collect the produced water from the already built sedimentation tank and then treat and dispose or reuse onsite the treated produced water. Therefore, this system promises a possible treatment system that more Oil sensible from an ecological and economical point of well Storage view without the need to construct expensive sewer tank River Sedimentation