Karakterisasi Reservoar Hidrokarbon pada Lapangan “Tab” dengan Menggunakan Pemodelan Inversi Impedansi Akustik

Research has been performed with the characterization of hydrocarbon reservoir in “TAB” field using acoustic impedance inversion modeling. Acoustic impedance (AI) is a rock's ability to parse seismic waves that is the product results from rock density and velocity. Acoustic impedance also influenced by the type of litology, pressure, temperature, porosity and fluid content. This research used AI inversion method because a result of this inversion can give a imaging of the actual subsurface conditions, so that it can mapping the distribution of porosity reservoir target. The purpose of this research is determine value of acoustic impedance inversion results in the reservoir, estimate value of porosity a rocks in the reservoir and mapping the pattern of spread reservoir through analysis of acoustic impedance and porosity values. with comparing the results of inversion from some inversion modeling such as Bandlimited, Model Based and Linear Programming Sparse-Spike, so used is linear programming sparse spike model. The result of linear programming sparse spike model showing good correlation is 0.927 and the small error is 0.440 and does not depend on initial model, so it is good to used for targets that have a high reflectivity value. The results of inversion showing acoustic impedance located in low impedance zone between 2000 m/s*gr/cc - 3458 m/s*g/cc with depth around 1500 to 1700 ms. From this results has been slicing of the data. This slicing data is done with a window on 10 ms under the horizon, 20 ms under the horizon, and 30 ms under the horizon. Distribution of porosity inversion results is done by using 7 attribute. The results of porosity distribution obtained an average of 30%. Slicing porosity that shows the acoustic impedance values located in low anomaly which have a high porosity

The Effect Of Problem Posing Learning Model On Student's Mathematic Reasoning Ability

This research is an experimental research because the treatment is tested and its effect is measured on the sample groups. The experimental design used in this study was a non-equivalent pretest and posttest control group design. The population in this research were all students of senior high school (SMA) in Kutalimbaru in class IX which consisted of 323 students and 2 classes were randomly selected from 8 available classes. To obtain the data, an instrument was used, namely a set of mathematical reasoning tests in the form of descriptions that were valid and reliable. Furthermore, to determine whether or not there is an effect of mathematical reasoning before and a lesson, statistical analysis of the Independent Sample t-test was carried out. The results of the research show that problem posing learning significantly improves students' mathematical reasoning abilities when compared to before learning. It can be concluded that there is an effect of the problem possing learning model on students' mathematical reasoning abilities

A previously unidentified fault revealed by the February 25, 2022 (Mw 6.1) Pasaman Earthquake, West Sumatra, Indonesia

A destructive earthquake (Mw 6.1) struck Pasaman, West Sumatra, Indonesia, on 25 February 2022, resulting in at least 18 deaths and damage to 1765 buildings. Our relocated foreshock, mainshock, and aftershocks and their source mechanisms reveal a previously unknown ∼20 km long segment of the Sumatran Fault as a result of dextral strike-slip motion (strike N132oE and dip 72oSW) along what we have called the Kajai Fault. The inverted rupture model indicates a single, compact asperity with an approximate depth range of 2–11 km. This asperity extends ∼14 km along strike, and ∼9 km in the down-dip direction. The Coulomb stress change of the mainshock shows that areas to the north and south experienced an increase in stress, which is consistent with the observed aftershock pattern. The nearby Great Sumatran Fault segments (Angkola and Sumpur) experienced a significant increase in stress without any accompanying aftershocks, which likely increases the risk of them rupturing in the future