Overpressure Characteristics In Pertamina's Area In The North Sumatra Basin

Hutasoit, Lambok M.; Suseno, Weling; Siahaan, Darius; Ramdhan, Agus M.; Goulty, N. R.; Syaiful, Mohammad; Bachtiar, Andang; Iskandar, Irwan; Hendarmawan, Hendarmawan; Sadirsan, Wuryadi; Arifin, Maikel; Bahesti, Fatrial; Endarmoyo, Kharisma

doi:10.29118/ipa.0.13.g.153

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This, however, does not correspond to a high overpressure magnitude, as commonly expected and identified by some studies in several of Indonesia sedimentary basins (e.g. Ramdhan and Goulty, 2011;Hutasoit et al, 2013;Ramdhan and O'Connor, 2022).…”

Section: Pore Pressure Regimementioning

confidence: 46%

Pore Pressure and Compartmentalization of Carbonate Reservoirs in Northern Madura Platform - East Java Basin, Indonesia

Suryana,

Hutasoit,

Ramdhan

et al. 2023

Indonesian J. Geosci.

View full text Add to dashboard Cite

Understanding pore pressure characteristics in carbonate reservoirs is essential, because it concerns all aspects of subsurface, drilling, and occupational safety, as well as the environment in oil and gas exploration and exploitation. In this study, the pore pressure regime and connectivity of the carbonate reservoir (compartmentalization) of Kujung and Ngimbang Formations in the northern Madura Platform of East Java Basin are characterized by utilizing direct pressure data and wireline logs from five wells. The result shows that both hydrostatic and slight overpressure conditions are found in these formations, further indicating the presence of carbonate compartmentalization. The magnitudes of overpressure, however, are mostly very low, with an average of ~37 psi. Four compartmentalized carbonates are identified based on the presence of different pressure gradients in the water leg. The slight overpressure in the carbonates is likely owing to pressure transference from overpressured shale at depth. In addition, by using acoustic impedance from seismic, the depositional environments of the carbonates are interpreted as lagoon and tidal flat. These environments support the occurrence of patch reef carbonate buildups in the Kujung and Ngimbang Formations, which later become a good environment for overpressure generation and carbonate reservoir compartmentalization. Keywords: carbonates, compartmentalization, depositional environment, slight overpressure

show abstract

Section: Pore Pressure Regimementioning

confidence: 46%

Pore Pressure and Compartmentalization of Carbonate Reservoirs in Northern Madura Platform - East Java Basin, Indonesia

Suryana,

Hutasoit,

Ramdhan

et al. 2023

Indonesian J. Geosci.

View full text Add to dashboard Cite

show abstract

“…Based on the crossplot density (gr/cc) versus transit time (msec/m) it shows that the Upper Baong Formation is located in the smectite rich mud rock as a low overpressure zone, while the overpressure is present in the Lower Baong Formation which is located in the kaolinite + illiterich. Thus, it can be concluded that the overpressure in the Lower Baong Formation is caused by the unloading mechanism, due to the smectite to illite/kaolinite transformation (Hutasoit et al 2013). Overpressure characteristics in the Tamiang Sub-basin, North Sumatra Basin indicates that there are two overpressure mechanisms, namely the loading mechanism caused by the rapid sedimentation rate in the basin and the unloading mechanism caused by clay diagenesis and hydrocarbon generation (Yosandian et al 2014).…”

Section: Mineralogy Analysismentioning

confidence: 99%

“…The characteristics of overpressure in the North Sumatra Basin are divided into two overpressure conditions in the Baong Formation, namely the Upper Baong Formation as a mild overpressure zone and the Lower Baong Formation as a high overpressure zone. From the results of previous studies, an interesting phenomenon was found, namely in several wells in the North Sumatra Basin there were sonic log and resistivity logs reversals, each of which became high sonic and low resistivity (Hutasoit et al 2013). It is proven that the well drilling in the North Sumatra Basin is in the overpressure zone, although the use of low mud density does not cause significant problems which indicates a mild overpressure zone.…”

Section: Introductionmentioning

confidence: 96%

Overpressure mechanism prediction based on well log and mineralogy analysis from drill cuttings of well NSE-001 in the North Sumatra Basin area, Indonesia

Buntoro

Rahmad

Asmorowati

et al. 2022

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

The well NSE-001 is an exploration well located in the North Sumatra Basin, Indonesia, which penetrates several formations with overpressure zones that have the potential as a drilling hazard in this area. The results of the pore pressure fracture gradient model show that the response of the wireline log data of well NSE-001 based on the normal compaction trend has two types of overpressure mechanisms, namely loading and unloading. Rapid sedimentation in the development of the Lower Baong Formation and Upper Baong Formation as thick and massive shale sequences in the North Sumatra Basin is the main factor in the generation of an overpressure zone with a loading mechanism. This correlates with the travel time in the sonic log which is relatively constant with response to the normal compaction trend at depth intervals of 620–1500 mMD (from the Middle Baong Sand Formation to the Top Gebang Sand Formation). The presence of sillimanite and kaliophilite minerals in bulk analysis from drill cuttings at depth intervals of 2200–3820 mMD contributed to the generation of hydrocarbon, while clay analysis showed that the mineral content of kaolinite + illite as alteration product (clay diagenesis) was higher than the mineral content of smectite. The results of the mineralogy analysis (bulk and clay) correlated with the response of the wireline log data of well NSE-001 to the normal compaction trend, which showed that at depth interval of 1500 m to 3200 mMD (from the Top Gebang Sand Formation to the Top Upper Belumai Formation) is an overpressure zone with an unloading mechanism, which was characterized by fluid expansion caused by clay diagenesis and possibly hydrocarbon generation.

show abstract

“…Ramdhan et al (2018) recognized the regression as the evidence of active lateral reservoir drainage in the area. Hutasoit et al (2013) investigated overpressure characteristics in the Aru Field, North Sumatra Basin, and they obsserved that there were two overpressure conditions in the Baong Formation, i.e. mild overpressure in the Upper Baong and high overpressure in the Lower Baong.…”

Section: Introductionmentioning

confidence: 99%

Wireline Log Responses, Mudweight, Clay Mineralogy, and Implied Overpressure Condition: Insights from Aru Field, North Sumatra Basin

Syaiful

Hutasoit

Ramdhan

et al. 2020

Indonesian J. Geosci.

View full text Add to dashboard Cite

This paper comprehensively discusses overpressuring in the North Sumatra Basin by using wireline log, drilling events and parameters, and clay mineralogical data. It shows an interesting phenomenon related to overpressuring in this basin, i.e. strong log reversals indicating high overpressure, yet the mudweight used during drilling was relatively low, indicating low overpressure with no significant drilling events noted in the final well report.The result of the study shows that wireline log is the best parameter to imply overpressure magnitude. Regarding low mudweight in the strong log reversal zone, it would be elucidated that the drilling in that zone was in underbalance condition with respect to shale pressure, but not to sandstone pressure. The sandstone pressure is interpreted to be lower than shale pressure due to lateral drainage process. By applying the Eaton's method, the estimated maximum overpressure magnitude in the Baong Formation is in the range of 1,594-3,185 psi. or equivalent to the mudweight of 1.61-192 g/cm 3. The analysis of wireline log in combination with clay mineralogical data shows that there are two compaction lines in the studied area, i.e. smectitic and illitic compaction lines. The cross-plot of density and sonic logs in shale section suggest that the cause of overpressure was loading mechanism. The scanning electron microscope (SEM) image confirms that in overpressure zone, grain to grain contact is still able to be observed fairly well, inferring that loading mechanism is really the cause of overpressure in the studied area.

show abstract

Overpressure Characteristics In Pertamina's Area In The North Sumatra Basin

Cited by 4 publications

References 0 publications

Pore Pressure and Compartmentalization of Carbonate Reservoirs in Northern Madura Platform - East Java Basin, Indonesia

Pore Pressure and Compartmentalization of Carbonate Reservoirs in Northern Madura Platform - East Java Basin, Indonesia

Overpressure mechanism prediction based on well log and mineralogy analysis from drill cuttings of well NSE-001 in the North Sumatra Basin area, Indonesia

Wireline Log Responses, Mudweight, Clay Mineralogy, and Implied Overpressure Condition: Insights from Aru Field, North Sumatra Basin

Contact Info

Product

Resources

About