Pembentukan H2S bisa bermacam2, Suhu pembentukan H2S memang sekitar 120-140. Jadi kalau suhunya sudah mencapai 150 memang ada kemungkinan mendapatkan H2S. Saya sendiri belum tau apakah H2S juga ikutan bermigrasi seperti gas. Kalau iya berarti suhu bukan lagi pengontrol bakalan dijumpai masalah HS2 atau tidak di kedalaman itu ?
dibawah aku ambil dari : http://www.gaschem.com/evalu.html Silahkan di klick. disitu ada juga bagaimana pembentukan C02 dll. RDP ...................... A variety of discrete sources for H2S in petroleum have been identified (e.g., Orr, 1977) including: Bacterial reduction of sulfate to H2S. The sulfate can be from connate waters, anhydrite dissolution, injected seawater, or pyrite oxidation by injected water. Bacterial sulfate reduction typically does NOT result in gases containing >5% H2S. Thermal decomposition of sulfides in kerogen and/or oil (especially in clay-poor, sulfur-rich source rocks). This process typically does NOT result in gases containing >5% H2S. Thermochemical reduction of sulfate to H2S (TSR). TSR is the reaction of sulfate minerals (primarily anhydrite) and hydrocarbons (beginning at temperatures of 120-140 deg. C) to form H2S and calcium carbonate. Because anhydrite is often associated with carbonate sequences, TSR is commonly associated with deep, hot, carbonate reservoirs and/or source rocks. TSR is the most important process for formation of high-H2S gases (>10% H2S). The highest concentrations of H2S are found in deep, post-mature gases from carbonate sources (e.g., deep Smackover gases in Texas; Worden et al., 1995) where TSR is active. A variety of hydrocarbons can be involved in TSR (e.g., Manzano et al., 1997), but a general form for the reaction is: CaSO4 +CH4 CaCO3+H2S+H2O To assess the likelihood of encountering significant H2S in a given area, a variety of factors must be considered, including: Reservoir temperature (bacterial sulfate reduction is typically limited to temperatures of <80o C; and TSR is limited to temperatures above 120-140 o C). Availability of sulfate (necessary for both bacterial sulfate reduction and TSR) Potential sinks for H2S, such as pyrite formation in the reservoir or along the migration path by reaction of the H2S with iron-bearing silicates and/or carbonates. To assess the origin of encountered H2S, the above factors can be considered along with other lines of evidence, such as Examination of the distribution and form of pyrite in a reservoir (implications for H2S scavenging and pyrite oxidation). Microbiological studies of produced waters (to further assess the potential for in-reservoir bacterial sulfate reduction). Sulfur isotopic data for the H2S, organic sulfur compounds in the associated oil, and the sulfate in associated water (Krouse, 1977; Thode, 1981). Modeling of the aqueous chemistry of the rock/water/petroleum interactions in a given reservoir. On 11/18/05, Darman, Herman H BSP-TSX/4 <[EMAIL PROTECTED]> wrote: > Kar, > > Wuah... jadi tambah bingung khan... sorry, aku ngak tau banyak.. makanya > nanya. > > Herman > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > Sent: 18 November 2005 08:03 > To: [email protected] > Cc: [email protected] > Subject: Re: [iagi-net-l] H2S in HT well > > > Maaf Mas Herman bukannya jawab...malah nambah pertanyaannya... > > Bagaimana sih terjadinya H2S dalam formasi...apakah ada kriteria geologi > khusus agar terbentuk H2S....? > kalau Pak Awang dulu pernah cerita tentang kontrol karbonat terhadap CO2, > apakah juga ada kontrol geologi terhadap H2S ? > > Regards > > Kartiko-Samodro > Telp : 3852 > > > > |---------+----------------------------> > | | "Darman, Herman H| > | | BSP-TSX/4" | > | | <[EMAIL PROTECTED]| > | | ell.com> | > | | | > | | 18/11/2005 07:35 | > | | AM | > | | Please respond to| > | | iagi-net | > | | | > |---------+----------------------------> > > >-----------------------------------------------------------------------------------------------------------------| > | > | > | To: <[email protected]> > | > | cc: > | > | Subject: [iagi-net-l] H2S in HT well > | > > >-----------------------------------------------------------------------------------------------------------------| > > > > > Rekan-rekan, > > Ada yang pengalaman dengan H2S di High temperature wells? Ada kawan yang > mengatakan bahwa kalau kita melakukan pengeboran pada objektif yang suhunya > lebih dari 160 o C, maka akan selalu ditemukan H2S. Waktu drilling mungkin > tidak terdeteksi tapi setelah produksi 1-2 hari H2S ini akan muncul dan > tentunya menimbulkan masalah. > > Herman Darman > --------------------------------------------------------------------- To unsubscribe, send email to: iagi-net-unsubscribe[at]iagi.or.id To subscribe, send email to: iagi-net-subscribe[at]iagi.or.id Visit IAGI Website: http://iagi.or.id IAGI-net Archive 1: http://www.mail-archive.com/iagi-net%40iagi.or.id/ IAGI-net Archive 2: http://groups.yahoo.com/group/iagi Komisi Sedimentologi (FOSI) : Ratna Asharina (Ratna.Asharina[at]santos.com)-http://fosi.iagi.or.id Komisi SDM/Pendidikan : Edy Sunardi(sunardi[at]melsa.net.id) Komisi Karst : Hanang Samodra(hanang[at]grdc.dpe.go.id) Komisi Sertifikasi : M. 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