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).

scholarly journals The method for prediction of formation pore pressure based on mechanical specific energy theory

2021 ◽  
Vol 859 (1) ◽  
pp. 012004
Author(s):  
Lingdong Li ◽  
Bin Guan ◽  
Ruiqing Ming ◽  
Xiaoning Zhang ◽  
Jianli Zhang ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Specific Energy ◽  
Mechanical Specific Energy ◽  
Energy Theory ◽  
Formation Pore Pressure

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.

Pore-Pressure Estimation by Use of Mechanical Specific Energy and Drilling Efficiency

2017 ◽  
Vol 32 (02) ◽  
pp. 097-104 ◽  
Author(s):  
Reza Majidi ◽  
Martin Albertin ◽  
Nigel Last
Keyword(s):  
Pore Pressure ◽  
Specific Energy ◽  
Mechanical Specific Energy ◽  
Pressure Estimation

scholarly journals Developing a new approach for the anticipation of subsurface pressure in three oil wells from various fields in Iraq

2021 ◽  
Author(s):  
Rafid K. Abbas
Keyword(s):  
Pore Pressure ◽  
Specific Energy ◽  
Mean Squared Error ◽  
Well Logs ◽  
Percentage Error ◽  
Drilling Process ◽  
Special Equipment ◽  
Suggested Approach ◽  
Lost Circulation ◽  
Mechanical Specific Energy

AbstractSubsurface pressure quantification is the main goal for all drilling engineers due to its vital importance to minimizing drilling costs and preventing various excavating dilemmas such as stuck pipe, pipe collapsing, lost circulation, and well kick. Formation pressure is measured directly in producing hydrocarbon zones using special equipment; however, it is difficult to obtain pore pressure measurements in other intervals; therefore, many approaches were suggested and developed to anticipate the geopressure due to its importance on the drilling operation. Traditionally, Eaton's method is the most widely used for geopressure anticipation from well logs. In the current study, a new proposed formula for geopressure determination was derived from the modified Eaton's equation which is based on the inception of the mechanical specific energy. The study was applied on three oil-producing wells from different fields in Iraq (Missan C, West Qurna 15, and Zubair 171). The estimated subsurface pressure from the new suggested approach was validated by comparison with the actual in situ subsurface pressure obtained from Drill Stem Test (DST) and Repeated Formation Test (RFT). Statistical analysis is used for the validation by applying Mean squared error (MSE) and Mean Absolute percentage Error (MAE). Encouraging results were obtained from the present research for all wells being studied. The main finding of the current work is involving a new parameter (mechanical specific energy) for subsurface pressure determination, where it was not included in the previous techniques of geopressure equations. It was found that the value of exponent (m) in the new proposed equation has a significant influence on the predicted geopressure, where (m) varies from 0.1626 to 0.6896 depending on the type of the excavated rock plus the materials that the drill bit is manufactured of, where the interaction between these components is vital. The present work could be a useful method when planning to excavate a new well adjacent to the area of the investigated wells, where special well logs are unavailable for pore pressure measurement and suitable usage of mud weight is highly needed for the overall drilling process.

scholarly journals Wellbore Breakouts Prediction from Different Rock Failure Criteria

2020 ◽  
Vol 26 (3) ◽  
pp. 55-64
Author(s):  
Aows Khalid Neeamy ◽  
Nada Sabah Selman
Keyword(s):  
Pore Pressure ◽  
Failure Criteria ◽  
Rock Failure ◽  
Vertical Wells ◽  
Wellbore Instability ◽  
Rock Failure Criteria ◽  
Drilling Operations ◽  
Coulomb Criterion ◽  
Productive Time ◽  
Critical Limits

One of the wellbore instability problems in vertical wells are breakouts in Zubair oilfield. Breakouts, if exceeds its critical limits will produce problems such as loss circulation which will add to the non-productive time (NPT) thus increasing loss in costs and in total revenues. In this paper, three of the available rock failure criteria (Mohr-Coulomb, Mogi-Coulomb and Modified-Lade) are used to study and predict the occurrence of the breakouts. It is found that there is an increase over the allowable breakout limit in breakout width in Tanuma shaly formation and it was predicted using Mohr-Coulomb criterion. An increase in the pore pressure was predicted in Tanuma shaly formation, thus; a new mud weight and casing programs are proposed to overcome such problems in the drilling operations in field developments plans.

Application of geostatistical seismic inversion in reservoir characterization of Sapphire gas field, offshore Nile Delta, Egypt

2019 ◽  
Vol 38 (6) ◽  
pp. 474-479
Author(s):  
Mohamed G. El-Behiry ◽  
Said M. Dahroug ◽  
Mohamed Elattar
Keyword(s):  
Reservoir Characterization ◽  
Nile Delta ◽  
Seismic Inversion ◽  
Reservoir Modeling ◽  
Connectivity Analysis ◽  
Gas Field ◽  
Geostatistical Inversion ◽  
Well Data ◽  
Reservoir Connectivity ◽  
Inversion Techniques

Seismic reservoir characterization becomes challenging when reservoir thickness goes beyond the limits of seismic resolution. Geostatistical inversion techniques are being considered to overcome the resolution limitations of conventional inversion methods and to provide an intuitive understanding of subsurface uncertainty. Geostatistical inversion was applied on a highly compartmentalized area of Sapphire gas field, offshore Nile Delta, Egypt, with the aim of understanding the distribution of thin sands and their impact on reservoir connectivity. The integration of high-resolution well data with seismic partial-angle-stack volumes into geostatistical inversion has resulted in multiple elastic property realizations at the desired resolution. The multitude of inverted elastic properties are analyzed to improve reservoir characterization and reflect the inversion nonuniqueness. These property realizations are then classified into facies probability cubes and ranked based on pay sand volumes to quantify the volumetric uncertainty in static reservoir modeling. Stochastic connectivity analysis was also applied on facies models to assess the possible connected volumes. Sand connectivity analysis showed that the connected pay sand volume derived from the posterior mean of property realizations, which is analogous to deterministic inversion, is much smaller than the volumes generated by any high-frequency realization. This observation supports the role of thin interbed reservoirs in facilitating connectivity between the main sand units.

scholarly journals A new method for correcting temperature log profiles in low-enthalpy plays

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Sandra Schumacher ◽  
Inga Moeck
Keyword(s):  
Input Parameter ◽  
New Method ◽  
Geothermal Resources ◽  
The North ◽  
Deep Wells ◽  
Thermal Disturbance ◽  
Drilling Operations ◽  
Crucial Information ◽  
Well Data ◽  
Drilling Time

Abstract Temperature logs recorded shortly after drilling operations can be the only temperature information from deep wells. However, these measurements are still influenced by the thermal disturbance caused by drilling and therefore do not represent true rock temperatures. The magnitude of the thermal disturbance is dependent on many factors such as drilling time, logging procedure or mud temperature. However, often old well reports lack this crucial information so that conventional corrections on temperature logs cannot be performed. This impedes the re-evaluation of well data for new exploration purposes, e.g. for geothermal resources. This study presents a new method to correct log temperatures in low-enthalpy play types which only requires a knowledge of the final depth of the well as an input parameter. The method was developed and verified using existing well data from an intracratonic sedimentary basin, the eastern part of the North German Basin. It can be transferred to other basins with little or no adjustment.

Sign in / Sign up

Export Citation Format

Share Document