Petroleum Engineering – Exploration
Ali Jelvegarfilband; Mohammad Ali Riahi; Majid Bagheri
Abstract
The petrophysical parameters of the Ghar Formation are characterized in this study. A combination of pre-stack seismic data gathers and well-log data is used to estimate water saturation and shale volume in the Ghar reservoir. For such a purpose, first, the highest possible correlation between the well ...
Read More
The petrophysical parameters of the Ghar Formation are characterized in this study. A combination of pre-stack seismic data gathers and well-log data is used to estimate water saturation and shale volume in the Ghar reservoir. For such a purpose, first, the highest possible correlation between the well logs and the seismic inverse data was established. After extracting the best wavelet, an accurate relationship between the estimated and the values from core data was obtained. Secondly, using the data of another well, the validity of the constructed model was examined. The results showed that the combination of three attributes of instantaneous cosine of phase, √(Z_P ), and √(V_P ) is suitable to estimate the shale volume of the reservoir with considerable accuracy with a correlation coefficient of about 70%. Although the two layers in the Ghar section have a shale volume of about 10%, in general, the shale volume in the reservoir area is negligible. The logarithm of the ratio of compressional wave velocity to shear wave velocity attribute shows the highest correlation, about 62%. Finally, validation of the results of the mentioned properties with unintroduced well-log data showed an accuracy of about 90% in prediction.
Petroleum Engineering
Amir Gharavi; Mohamed Hassan; Hesam Zarehparvar Ghoochaninejad; John Fianu; Michael Kenomore; Amjad Shah; James Buick
Abstract
Since the development bloom in unconventional reservoirs in North America, total organic carbon (TOC) has become a more essential parameter, as the indicator of the efficiency of these reservoirs. In this paper, by using conventional well logs and NMR log data, the TOC content of an unconventional reservoir ...
Read More
Since the development bloom in unconventional reservoirs in North America, total organic carbon (TOC) has become a more essential parameter, as the indicator of the efficiency of these reservoirs. In this paper, by using conventional well logs and NMR log data, the TOC content of an unconventional reservoir in West Africa is estimated. Passy’s, Issler’s, and Schmoker’s methods were used as indirect wireline methods to estimate TOC content, along the well paths. Afterward, NMR log data, as a direct method, was used to provide more precise calculations of TOC. Both methods showed almost similar trends, with the NMR method indicating lower values for the TOC. Then, an adjusted Schmoker equation was proposed, which showed the best fit between NMR and conventional well logs results. By using the equation, the TOC content was calculated in three other wells, where NMR data were unavailable. The results were then used to prepare a 3D model of the TOC distribution, within the reservoir.
Asad Zia; Muhammad Awais; Muhammad Ishaq; Sardar Hamid; Naveed Akhtar; Lawangin Sheikh
Abstract
The petrophysical analysis of the early Eocene Sui Main Limestone (SML) has been conducted in Kharnhak-1 well for the prospect of the hydrocarbon exploration of the Khairpur-Jacobabad High, Middle Indus Basin, Pakistan. The petrophysical analysis of SML is carried out on the basis of well logs including ...
Read More
The petrophysical analysis of the early Eocene Sui Main Limestone (SML) has been conducted in Kharnhak-1 well for the prospect of the hydrocarbon exploration of the Khairpur-Jacobabad High, Middle Indus Basin, Pakistan. The petrophysical analysis of SML is carried out on the basis of well logs including gamma ray, spontaneous potential, resistivity, neutron, and density logs. These analyses lead to interpreting the vertical distribution of porosity and permeability in order to measure the reservoir potential of the SML. The Archie equation was used to assess the petrophysical characteristics. The SML has good porosity and poor permeability with positive correlation coefficient between the two parameters. The average volume of shale is 18%. The log signature of SML shows dominance of carbonates (limestone). The reservoir quality of the SML in Kharnhak-1 well is such that it is 77% water saturated. The porosity (x) varies inversely with formation resistivity factor (F) and compressional wave velocity (Vp). However, F and Vp are directly related with each other. Thus, the electric and elastic properties of the carbonate rocks can be influenced by postdepositional alterations, which include porosity enhancement and reduction processes respectively.
