Compressibilitas UAS_.pptx - Modul II Karakteristik Batuan Reservoir M.G Sri Wahyuni JURUSAN TEKNIK PERMINYAKAN FAKULTAS TEKNOLOGI KEBUMIAN DAN ENERGI

# Compressibilitas UAS_.pptx - Modul II Karakteristik Batuan...

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Modul II Karakteristik Batuan Reservoir 06/16/2020 KBR _UAS_ Ibu Yun1i 1 JURUSAN TEKNIK PERMINYAKAN FAKULTAS TEKNOLOGI KEBUMIAN DAN ENERGI UNIVERSITAS TRISAKTI M.G Sri Wahyuni
KOMPRESIBILITAS POROSITAS BATUAN SEDIMEN === AKAN BERKURANG karena KOMPAKSI akibat BERAT BATUAN DIATASNYA “Over Burden”
Hubungan porositas awal dengan tekanan over burden
Isothermal Compressibility C: Coefficient of Isothermal Compressibility oilfield units: 1/psia V: Volume , oilfield units: f 3 p: Pressure exerted on material oilfield units: psia - Negative sign in equation determined by V/ p term, to force the coefficient C to be positive - Volume is a function of pressure only (temperature is constant, and amount of material is constant) p V V 1 C
Formation Compressibility Matrix Compressibility ( C m ): relative change in volume of solid rock material (grain volume) per unit pressure change (usually C m 0). Pore Compressibility ( C f ): relative change in pore volume per unit pressure change. Bulk Compressibility ( C b ): relative change in bulk volume per unit pressure change ( usually D V b D V p ). Significant decrease in bulk volume can cause subsidence.
1. Under static conditions, downward overburden force must be balanced by upward forces of the matrix and fluid in pores 2
3. Pressure Gradients, Normal Reservoirs: dp o /dZ = 1.0 psia/f dp/dZ = 0.465 psia/f 4. As fluids are produced from reservoir, fluid pressure (p) usually decreases while overburden is constant, and: (a) force on matrix increases ( “net compaction pressure”, p m =p o -p) (b) bulk volume decreases, and (c) pore volume decreases.
Formation Compressibility Pore Volume Change - Continued ) p (p C 1 V V ) p (p C V V p p V V V 1 C p V V 1 p V V 1 C 1 2 f p1 p2 1 2 f p1 p 1 2 p1 p2 p1 f p p p p f D D D d d
WETTABILITAS (sifat kebasahan) DEFINISI : Wettabilitas adalah : KECENDERUNGAN BATUAN / PADATAN UNTUK DIBASAHI OLEH SUATU FLUIDA “ Wetabilitas merupakan akibat adanya interaksi antara fluida dan padatan Batuan reservoir ( sand stone, limestone, dolomit dll) merupakan padatan” Fluida reservoir ( minyak ,air ,gas) merupakan fluida”
Pada umumnya reservoir mengandung 2 – 3 macam fluida Bila ada 2 atau lebih fluida dalam reservoir maka akan timbul 3 gaya yang aktif pada fluida tersebut. = dapat digambarkan seperti gambar dibawah ini .
Dimana : = contact angle between the oil / water/solid interface measured through the more dense phase, degrees so = interfacial energy between the solid and oil, milli-Newtons/m or dynes/cm sw = interfacial energy between the solid and water milli-Newtons /m or dynes/cm wo = interfacial energy (interfacial tension) between the water and oil, milli-Newtons/m or dynes/cm