Browsing by Author "Jayasinghe, WMTU"

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    item: Conference-Full-text
    Development of a Pore Pressure and Fracture Pressure Gradient Prediction Model for few exploration blocks in Mannar and Cauvery Basins, offshore Sri Lanka
    (2015-08-14) Jayasinghe, JMSTW; Kurukulasuriya, AC; Jayasinghe, WMTU; Wickrama, MADMG; Senadhira, AMADM; Ratnayake, NP
    Availability of a pore pressure and fracture pressure gradient prediction model for petroleum well drilling is a basis for safety, cost effectiveness and the efficiency of the overall drilling program. Petrophysical data and measured pressure data of four wells previously drilled in the Mannar basin and Cauvery basin were reviewed to establish such a model for few petroleum exploration blocks in Sri Lanka. The pore pressure gradient prediction strategies used for the analysis are, Hottman and Johnson method, Ben Eaton method and D-exponent method. Hubbert and Willis method, Ben Eaton method and Matthews and Kelly method are the fracture pressure gradient prediction strategies used. Area specific variables including Poisson ratio and matrix stress coefficient were determined prior to fracture pressure gradient prediction. After a statistical analysis and comparison with well log data, a combination of Hottman and Johnson method and D-exponent (Eaton) method was selected as the best suited pore pressure gradient prediction model for the drilling area. The analysis of fracture pressure gradient strategies found that the Ben Eaton method is the best suited method for the area. After determining the suitable prediction methods, the Petrel software was used to visually interpret and analyze the results obtained. The research findings will help for future drilling operations and well planning in the specified area in Mannar and Cauvery basins.
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    item: Conference-Full-text
    Development of a pore pressure and fracture pressure gradient prediction model for few exploration blocks in Mannar and Cauvery basins, offshore Sri Lanka
    (Department of Earth Resources Engineering, 2014-07) Jayasinghe, JMSTW; Kurukulasuriya, AC; Jayasinghe, WMTU; Wickrama, MADMG; Senadhira, AMADM; Ratnayake, NP; Hemalal, PVA
    Availability of a pore pressure and fracture pressure gradient prediction model for petroleum well drilling is a basis for safety, cost effectiveness and the efficiency of the overall drilling program. Petrophysical data and measured pressure data of four wells previously drilled in the Mannar basin and Cauvery basin were reviewed to establish such a model for few petroleum exploration blocks in Sri Lanka. The pore pressure gradient prediction strategies used for the analysis are, Hottman and Johnson method, Ben Eaton method and D-exponent method. Hubbert and Willis method, Ben Eaton method and Matthews and Kelly method are the fracture pressure gradient prediction strategies used. Area specific variables including Poisson ratio and matrix stress coefficient were determined prior to fracture pressure gradient prediction. After a statistical analysis and comparison with well log data, a combination of Hottman and Johnson method and D-exponent (Eaton) method was selected as the best suited pore pressure gradient prediction model for the drilling area. The analysis of fracture pressure gradient strategies found that the Ben Eaton method is the best suited method for the area. After determining the suitable prediction methods, the Petrel software was used to visually interpret and analyze the results obtained. The research findings will help for future drilling operations and well planning in the specified area in Mannar and Cauvery basins.
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    item: Conference-Abstract
    Pore-pressure and fracture pressure gradient prediction model for few exploration blocks in mannar and cauvery basins, Sri Lanka
    Jayasinghe, JMSTW; Kurukulasuriya, AC; Jayasinghe, WMTU; Wickrama, MADMG; Senadhira, AMADM; Ratnayake, NP
    Wellbore instability, kick and loss of circulation through fractures are the most significant problems observed during petroleum drilling. Selection of an appropriate mud weight is the key solution for these problems. To select a safe range of mud weights, the knowledge of formation pore pressure and fracture gradient of the drilling area is essential. This paper aims to find the most suitable fracture pressure gradient and pore-pressure models for Mannar and Cauvery basins in Sri Lanka. Three pore-pressure prediction strategies, namely, Hottman and Johnson ,1965 [4] method, Ben Eaton ,1975 [9]method and D-exponent method-Eaton ,1975 [9]and three fracture pressure gradient prediction methods, namely, Hubbert and Willis ,1957 [10] method, Matthews and Kelly (1967) method and Ben Eaton (1969 [6] method, were used in this research. Petro-physical data of four wells previously drilled in the Mannar basin and Cauvery basin in Sri Lanka were used to predict pore pressure and fracture pressure gradient using above methods. Then the predicted values were compared with the actual pressure values obtained from well log records of same wells. Area specific variables, including Poisson ratio and Matrix Stress Coefficient were determined prior to the fracture pressure gradient prediction. After determining the suitable prediction methods, a basin analysis software (Petrel), (Schlumberger, 2010.1) software was used to visually interpret and analyse the results. The results of the Pore-pressure analysis suggested that a combination of Hottman and Johnson method and D-exponent-Eaton method are suitable pore pressure prediction models for the study area. The analysis of fracture pressure gradient strategies found that the Ben Eaton method is the most suitable method to predict the fracture pressure gradient of the area.