scholarly journals Integrated Pore Pressure Model Estimation – Case Study of Jambi Sub-basin, South Sumatera, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012012
Author(s):  
Ahmad Farhan Farabi ◽  
Ignatius Sonny Winardhie ◽  
Noor Cahyo Wibowo
Keyword(s):  
Pore Pressure ◽  
Probabilistic Neural Network ◽  
Maximum Pressure ◽  
Model Estimation ◽  
Attribute Analysis ◽  
Zone Depth ◽  
Well Data ◽  
Productive Time

Abstract Pore pressure estimation is crucial in drilling wells for safety purposes also a very effective method for dealing with drilling accidents. Determination of overpressure is the main foundation in the evaluation to minimize the non-productive time (NPT). Here we present several models to generate pore pressure analysis of well from Jambi Sub-basin, South Sumatera, Indonesia. The model for estimation pore pressure is carried out by 3 methods: Eaton, Yan & Han, and Kan & Swan. Those methods will be compared to gain a more accurate model estimation within the study area. Kan and Swan’s model show the best fit for estimation because this method is suitable for the formation of tester like MDT/DST on higher frequency with parameter of C1 = 0.001 and C2 = 0.0003 for Jambi Sub-basin. The velocity data to construct the 3D pore pressure model was also validated with well data using multi-attribute analysis. The multi-attribute analysis used 2 algorithms, namely step-wise regression and probabilistic neural network (PNN). The analysis show that PNN has a better correlation compared to step-wise regression. The analysis shows the overpressure zone depth is ranges from 1700 – 2000m on Gumai Formation with maximum pressure around 6500 psi. The peak of overpressure dominated by Gumai and Talang Akar formation is caused by the loading mechanism because the rate of sedimentation on thick shale sequence is higher than the rate of dewatering on those formations.

Determination of Dynamic Limits for Rig Heave and Running Speed Based on Drilling Parameters, Well Data and Completion Tool Limitations - Case Studies

2021 ◽  
Author(s):  
Dmitri Gorski ◽  
Martin Kvernland ◽  
Knut Hals ◽  
Margrethe Blaaflat ◽  
Johannes Ladenhauf ◽  
...  
Keyword(s):  
Drill Pipe ◽  
Planning Software ◽  
Drilling Parameters ◽  
Industry Practice ◽  
Novel Method ◽  
Different Depths ◽  
Well Data ◽  
Productive Time

Summary A novel method of utilizing simulations of surge and swab induced by floating rig heave is presented in this paper. The intended applications are in well planning and follow-up of drilling and completion operations. We focus on rig heave during drill pipe connections when the rig's heave compensator cannot be engaged. The method consists of: (1) estimating a dynamic, well- and operation-specific, rig heave limit based on surge & swab simulations at different depths in a well and (2) clearly communicating the dynamic rig heave limit to the rig crew and onshore organization as a simple metric. We present cases where this novel methodology has been tested during the drilling and completion of two offshore wells in Norway, and we elaborate on the operators’ view of the method's advantages. We conclude that complementing the traditional fixed rig-specific heave limit with the dynamic one that is based on the properties of the actual well and the actual drilling/completion parameters offers an opportunity to improve management of risks related to breaching well pressure margins or damaging downhole equipment and to reduce costs through reduction of weather-related non-productive time. We show that the dynamic rig heave limit may differ significantly from well to well and also throughout the same well depending on the kind of operation in the well, depth in the well, well geometry and other parameters related to well and operation properties. Our conclusion is that care should be taken when generalizing a maximum allowed rig heave value as is the industry practice today. The benefits of utilizing dynamic well-specific rig heave limit should be assessed during well planning for any well drilled and completed from a floating rig. Well planning software existing today does not offer this functionality.

scholarly journals Drilling Optimization of Tight Sands and Shale Gas Reservoir in Jambi Sub-Basin Based on Pore Pressure Estimation Using Drilling Efficiency Mechanical Specific Energy (DEMSE) and Bowers Methods

2019 ◽  
Vol 125 ◽  
pp. 15001
Author(s):  
Benny Abraham Bungasalu ◽  
M. Syamsu Rosid ◽  
Don S. Basuki
Keyword(s):  
Pore Pressure ◽  
Specific Energy ◽  
Shale Gas ◽  
Seismic Inversion ◽  
Mechanical Specific Energy ◽  
Drilling Operations ◽  
Well Data ◽  
Tight Sand Gas ◽  
Productive Time ◽  
Pressure Analysis

The subsurface pressure analysis is used to detect the overpressure and problems in the well that will be drilled based on exploration well data. Various problems were found while drilling operations carried out on A and B wells, namely, Kick and Pipe sticking which cause a high Non-Productive Time (NPT). This research is conducted to identify the mechanism of overpressure formation in Tight Sand Gas and Shale Gas in the Jambi Sub-Basin. Furthermore, to predict pore pressure using the Drilling Efficiency and Mechanical Specific Energy (DEMSE) and Bowers method. The final result will be a 3D pore pressure cube in the area based on quantitative analysis of post-stack seismic inversion. The results of the pore pressure analysis from the wells and the 3D pore pressure model indicate that top of overpressure occurs in the Gumai Formation, then it is decreasing gradually approaching the hydrostatic pressure on the Basement. The mechanisms of overpressure are caused by under compaction, fluid expansion (kerogen maturation). The Gumai Formation and Talang Akar Formation are shale rocks so the type of mud weight that is well used is oil based mud (OBM).

Seismic pore pressure prediction without well data and poorly defined normal compaction trend lines: a case study from the Río Bravo Delta, Northern Mexico

2005 ◽  
Author(s):  
Juan C. Clarembaux ◽  
Marcelo Giusso ◽  
Roberto Gullco ◽  
Daniel Mujica ◽  
Carlos Carabeo Miranda ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Northern Mexico ◽  
Pore Pressure Prediction ◽  
Rio Bravo ◽  
Well Data

Integration of seismic attribute analysis and well data to identify depositional trends: A case study from Kuwait

2008 ◽  
Author(s):  
Srinivasa Rao Narhari ◽  
Mohamed Dawaas Al‐Ajmi ◽  
Saifullah Khan Tanoli ◽  
Bashar Al‐Qadeeri
Keyword(s):  
Seismic Attribute ◽  
Attribute Analysis ◽  
Well Data

Pore pressure assessment from well data and overpressure mechanism: Case study in Eastern Tunisia basins

2019 ◽  
Vol 38 (7) ◽  
pp. 830-843 ◽  
Author(s):  
Samah Adouani ◽  
Riadh Ahmadi ◽  
Mahmoud Khlifi ◽  
Dhaou Akrout ◽  
Eric Mercier ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Well Data

Interpretation of fractured zones using seismic attributes — Case study from Teapot Dome, Wyoming, USA

2016 ◽  
Vol 4 (2) ◽  
pp. T249-T260 ◽  
Author(s):  
Sarah Schneider ◽  
Christoph Georg Eichkitz ◽  
Marcellus Gregor Schreilechner ◽  
John C. Davis
Keyword(s):  
Fracture Network ◽  
Seismic Attributes ◽  
Seismic Attribute ◽  
Teapot Dome ◽  
Attribute Analysis ◽  
Discrete Fracture ◽  
Textural Attributes ◽  
Occurrence Matrix

We have used poststack seismic attributes to describe the fracture network of the naturally fractured Tensleep Formation at Teapot Dome, Wyoming, USA. The attributes include coherence, coherence based on spectral decomposed seismic data, attributes based on curvature, and textural attributes based on the gray-level co-occurrence matrix (GLCM). Results were compared with image log interpretations of four wells. Seismic attribute analysis allowed determination of strikes and dips as well as the intensity of fractures. The GLCM-based attributes proved especially valuable for building a discrete fracture network.

scholarly journals PORE PRESSURE ESTIMATION IN HARD UNLOADING-OVERPRESSURE ZONE USING SINGLE COMPACTION EQUATION, CASE STUDY: LOWER KUTAI BASIN

2018 ◽  
Vol 39 (2) ◽  
pp. 77-90
Author(s):  
Irawan Y Tribuana ◽  
Usep Mulyadi ◽  
Agus M Ramdhan ◽  
Asep H Rustam
Keyword(s):  
Pore Pressure ◽  
Measurement Data ◽  
Single Equation ◽  
Pore Pressure Prediction ◽  
Wireline Logs ◽  
Pressure Estimation ◽  
The Cost ◽  
Productive Time ◽  
Pressure Magnitude

Pore pressure estimation in hard-overpressure zone is very important in drilling activities. Correct and precise estimation are able to reduce the cost for drilling due to reduced non-productive time (NPT) and in increase in safety aspect while drilling. Pore pressure estimation is done by post-mortem analysis in exploration wells using validation points from pressure measurement data such as Drill Stem Testing (DST), Modular Dynamic Tester (MDT), and Repeat Formation Tester (RFT). A wireline logs data used for identification of the type of overpressure and predicts pore pressure magnitude in the shale section. Through the correlation between effective-stress and velocity, a single compaction equation was obtained for the Lower Kutai Basin with the value of : 5.097 * ? 0.854. By using this single equation, pre-drill pore pressure prediction activity will be more easy and could estimate pore pressure in hard-overpressure zone precisesly.

Influence of faulting on reservoir overpressure distribution in the Northern Carnarvon Basin

2015 ◽  
Vol 55 (1) ◽  
pp. 35
Author(s):  
Edward Hoskin ◽  
Stephen O'Connor ◽  
Stephen Robertson ◽  
Jurgen Streit ◽  
Chris Ward ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Hanging Wall ◽  
Foot Wall ◽  
Geological History ◽  
Pore Pressure Prediction ◽  
Northern Carnarvon Basin ◽  
Well Data ◽  
Carnarvon Basin

The Northern Carnarvon Basin has a complicated geological history, with numerous sub-basins containing varying formation thicknesses, lithology types, and structural histories. These settings make pre-drill pore pressure prediction problematic; the high number of kicks taken in wells shows this. Kicks suggest unexpected pore pressure was encountered and mudweights used were below formation pressure. The horst block penetrated by the Parker–1 well is focused on in this peer-reviewed paper. This horst is one of many lying along Rankin Trend’s strike. In this well, kicks up to 17.2 ppg (pounds per gallon) were taken in the Mungaroo reservoir. The authors investigate whether the kicks represent shale pressure—or rather, represent pressure transferred into foot-wall sandstones—by using well data from Forrest 1/1A/1AST1 and Withnell–1, and wells located in the Dampier Sub-basin and the hanging-wall to the horst. This anomalous pressure could result from either cross-fault flow from juxtaposed overpressured Dingo Claystone or transfer up faults from a deeper source. Using a well data derived Vp versus VES trend, the authors establish that the kicks taken in Parker–1 are more likely to result from pressure transfer using faults as conduits. These data lie off a loading trend and appear unloaded but likely represent elevated sand pressures and not in situ shale pressure. Pressure charging up faults in the Northern Carnarvon Basin has been recognised in Venture 1/1ST1, however, this paper presents a focused case study. Pressure transfer is noted in other basins, notably Brunei. From unpublished data, the authors believe that buried horst blocks, up-fault charging and adjacent overpressured shale may explain high reservoir pressures in other basins, including Nam Con Son in Vietnam.

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