bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishment of Appropriate Normal Compaction Trend NCT: A Critical Aspect for Reducing Uncertainty in 3D Pore Pressure Modelling.
Authors: Bhardwaj Nitin , Gunasekaran Karthikeyan , Kumar Ashutosh , Dutta Jayanta 
Published: April 2019

Abstract
In 3D Pore Pressure Modelling workflow, establishing appropriate Normal Compaction Trend (NCT) is not only critical but also requires the maximum extent of human interpretation and geological understanding. If not established appropriately, it can introduce substantial uncertainty in the final pore pressure prediction. Though, statistical algorithm techniques are available to establish it, the authors of this paper have demonstrated that establishing NCT manually based on geological logic and regional pressure understanding is much more reliable technique than pure statistical based approach.
In this paper, authors utilizes two different approaches in establishing Normal Compaction Trend (NCT) for the study area. First, based on pure statistical technique and second, a manual one based on combination of 3D velocity trends and regional geological pressure understanding. The 3D pore pressure volumes generated from the above two separate NCT’s are then checked for their conformance and agreement with the regional pressure data and understanding, including validation with post drill measured pressure data in the study area.
The results and analysis in the study area shows that, establishment of NCT based purely on statistical approach results in higher uncertainty in the 3D pore pressure estimation process. Whereas, manual NCT based on logic results in much more robust, reliable, and regionally consistent 3D pore pressure model with lower uncertainty. In our case study, the average uncertainty in the statistical NCT based 3D Pressures was ranging between 0.8 – 2.3 PPG when compared with actual pressures, while in the case of logic based manual NCT the average uncertainty was less than 1.0 PPG.
This case study indicates that in the offshore areas, particularly in areas where there is transition from shelf to slope to deepwater, it is advisable to use all the regional pressure knowledge and geological understanding in establishing the NCT, rather than adopting only the pure statistical methods.
Under Balanced Drilling: Experience in India
Authors: Motghare Prashant , Musale Amol , Desai Amit B. , Parmar Arvindbhai D. 
Published: April 2019

Abstract
Under Balanced Drilling (UBD) pilot project in the Heera and Mumbai High fields of Western offshore India was recently completed successfully. The objective of the project was to establish whether the technology can improve productivity performance in the reservoir section, avoid reservoir damage and thereby enhance oil production from the wells. This paper incorporates the drilling experiences and challenges faced during execution of this pilot project, the well design considerations and methodology, evaluation of the drilling fluid systems and also describes the tangible benefits of using this technology in the drilling of these sections and wells. In terms of the productivity gains from drilling these wells using UBD technology, through the sub-hydrostatic formations offshore Mumbai, the results were very positive. With the success and encouraging results from the pilot project, more wells are now planned, including wells in the losses-prone and depleted Mumbai High and Neelam fields, to incorporate the experiences of the learning curve.
Integrated Solutions to Maximize Asset Value for Mature Field Development: A Case Study
Authors: Abdulkarim Anar , Aki Ahmet , Al Jahwari Mohammed 
Published: April 2019

Abstract
Monitoring and re-evaluation of petrophysical attributes in a mature field under production for many decades is crucial for optimizing production and further development planning. In this case study, a multidisciplinary approach is deployed for formation evaluation and reservoir characterization using logging-while-drilling (LWD) sensors spanning formation volumetrics, fluid analysis, high-resolution image interpretation, and geomechanics to confirm remaining oil saturations and help identify recompletion intervals.
LWD technologies were used in four wells in Sahmah field of Oman to provide an integrated petrophysical and geomechanical field study using a bottomhole assembly (BHA) including gamma ray, resistivity, formation bulk density, thermal neutron, acoustic, high-resolution imaging, and formation pressure testing sensors. A deterministic multimineral petrophysical model was used to derive formation volumetrics and fluid analysis. Geomechanical interpretation used high-resolution microresistivity imaging, acoustic slownesses, and formation pressure data to verify principal stress orientations and to quantify pore pressure and horizontal minimum and maximum stress magnitudes. These data were then correlated with historical data to evaluate sweep efficiency and residual fluid saturations.
LWD sensors have proven to provide robust geological, petrophysical, and geomechanical data compared to previous traditional wireline data acquisition. High-resolution images facilitated fracture evaluation and the determination of the rock facies. Formation pressures were used to fine-tune the geomechanical parameters and depletion profile.
With the integration of historical data, remaining oil saturations were estimated, which enabled new completions intervals. Well test results and the production profiles further facilitated re-evaluation of the original petrophysical cutoffs for the calculation of the oil in place and remaining oil saturations. Reservoir petrophysical attributes were then updated, taking into account the pressure depletion intervals while honoring history matching to help design future well construction and development drilling.
The pilot case study helped better understand the flow units in this mature field and facilitated benchmarking future petrophysical data gathering requirements and optimization of the overall reservoir management strategy, including well-construction options to help minimize field development costs.
Petroleum System Based Integrated Exploration and Prospect Generation
Authors: Dubey Siddharth , Das Debjyoti 
Published: April 2019

Abstract
Identification of a prospect is normally done based on seismic interpretation and geological understanding of the area. However, due to the inherent uncertainties of the data we still observe in many cases that all key petroleum system elements are present, but still the drilled prospect is dry. Such failures are mostly attributed to a lack of understanding of seal capacity, reservoir heterogeneity, source rock presence and maturation, hydrocarbon migration, and relative timing of these processes. The workflow described in this paper aims to improve discovery success rates by deploying a more rigorous and structured approach. It is guided by the play-based exploration risk assessment process. The starting point is always that the process is guided by the the basic understanding of a mature kitchen should always be based on a regional scale petroleum systems model. However, while evaluating prospects, the migration and entrapment component of a prospect should always be investigated by means of a locally refined grid-based petroleum system model. The uniquepart of this approach is the construction of a high-resolution static model covering the prospects, which is built by using available well data, seismo-geological trends and attributes to capture reservoir potential. Additional inputs such as fault seal analysis also helps to understand prospect scale migration and associated geological risks. In the regional play and local prospect-scale petroleum system models, geological and geophysical inputs are utilized to create the uncertainty distribution for each input parameter which is required for assessing the success case volume of identified prospects. The evaluated risk is combined with the volumetric uncertainty in a probabilistic way to derive the risked volumetrics. It is further translated into an economic evaluation of the prospect by integrating inputs like estimated production profiles, appropriate fiscal models, HC price decks, etc. This enables the economic viability of the prospects to be assessed, resulting in a portfolio with proper ranking to build a decision-tree leading to execution and operations in ensuing drilling campaigns.
Introduction of SRI Technique for Paddy Growers as a Part of CBM-Raniganj Development
Authors: Tawde Vilas , Banerjee Monalisa 
Published: April 2019

Abstract

Objective/ Scope
Paddy cultivation contributes 12% of the total methane emitted in the environment by various sources. At EOGEPL, Systematic Rice Intensification (SRI) has been introduced among the paddy farmers which not only increased their crops’ yield but also controlled the emission of methane directly into atmosphere.

Method Procedures, Process
CBM Development requires numerous parcels of land. The farmers who were apprehensive about selling land for the CBM project, or those who were trying to get rid of their land as farming did not seem a good enough source of income, were targeted for this project. Training on the SRI method was conducted along with education on the benefits of the system from a farmer's perspective. In addition, the beneficiaries were given support in the form of seeds, rudimentary machinery and SOS medicines, required for the paddy farming.

Result, Observation, Conclusion
The result was awakening for the farmers. In comparison to the traditional method the yield of paddy increased from minimum 37% to maximum 83%, resulting in an increase net income of the farming community. The success factor for EOGEPL, was that by working with 37 farmers on total land area of 4.99 hectare, 45.37 tons of methane emission was controlled. It could be concluded from this project that, the SRI method has the capacity to address 3 major aspects of the modern day. At a time when due to increase of population per head availability of food grain is decreasing, SRI method can double the yield on the same area available. In addition, with decrease in required inputs i.e. the investment and growth of marketable output i.e. yield, the net income of the farmer increases. Most importantly, the practice of SRI controls methane emission which is responsible for greenhouse effect.

Additive Information
The additive information in this paper is that, a single move of SRI practice can address very important problems associated with a CBM-Project and can contribute to the nationwide movement of developing a clean environment and increasing the availability of food grain for the future with increase income to farmers.
Integrated Approach for Proper Resource Assessment of a Challenging Over-Pressured Gas Condensate Reservoir: Case Study of Analytical and Numerical Modeling of a Central Luconia Carbonate Field
Authors: Hajizadeh Mobaraki Alireza , Bashir Aamir , Shen Sow Chia , Deo Tewari Raj , B M Zakei Amran 
Published: April 2019

Abstract
Proper and reliable resource assessment of hydrocarbons in-place and recoverable volumes is one of the key factors in field development planning (FDP) and determines the commitments made to the host government for the reserves to be developed (RTBD). Many times, it is critical to update the resources and reserves of a producing asset through full field reviews (FFR) to gauge the production attainment and success of initial forecasts in FDP and also to locate any upside/locked-in potential.
Often uncertainties in the field development are expected to reduce as the field produces, but in many cases the results show otherwise due to lack/ inaccuracy of data or existing reservoir complexities. This paper elaborates how an integrated approach utilizing analytical methods (material balance, pressure and rate transient analysis) combined to numerical reservoir simulation is used for accurate resource assessment of an over-pressured gas condensate reservoir that suffers from lack of geological and petrophysical data, faulty production data measurement system and complex fluid and pressure behavior.
A comprehensive workflow comprising of different methodologies is used to harness the available geological, petrophysical, production and pressure data. Over-pressured and compressibility corrected gas material balance and pressure and rate transient analysis (RTA) are conducted using static and flowing data to encompass the existing uncertainties on resource numbers and generate low, base and high cases. The results of these methods are then successfully utilized to construct the dynamic reservoir model for evaluation of the upside and near field exploitation (NFE) potential. The results of the full field review lead to a 50% increase in the gas initially in-place compared to FDP volumes and a significant addition in the proven reserve. This increase in volumes was investigated through proactive surveillance for a period of time and was well supported by the reservoir and well performance.
A novel approach to numerically model the over-pressured gas reservoirs is developed using a simple concept of compressibility modifications supported by production data history match and analogue core data. The results of the study greatly benefited the production sharing contract (PSC) and lead to production enhancement from the field through a proper debottlenecking project.
Implications of Pressure Interference on Production Performance of Coal Bed Methane CBM wells
Authors: Thakuria Nityam 
Published: April 2019

Abstract
Well interference in unconventional CBM reservoirs is often desired. It reduces reservoir pressure; significantly increasing gas production through desorption. However, identifying interference between wells and extracting quantitative reservoir information using production data analysis is a challenge. The primary objectives of this study are to identify production characteristics of interfering CBM wells, evaluate reservoir parameters, demonstrate the application of interference data using field examples to predict well performance and develop guidelines to optimize geospatial well-pattern.
A field wide interference study has been undertaken to track changes in gas rate, water rate, wellhead pressure and fluid level in each well. An ‘event-based’ filter is applied to the dataset to correlate production behaviour of a well with any unplanned ‘event’ in its offset well. Planned well tests are then conducted to ascertain these evidences of interference. Using production data analysis of interfering wells, a set of semi-analytical correlations have been developed based on the transient drainage radius model to determine production-governing permeability of coal formation, and also quantify the flow contribution of natural fractures and reservoir matrix.
Preliminary analysis of the study demonstrates several forms of interference. Well specific field examples have been presented for each case. Interference between producing wells having long production history show a trend reversal in gas flow rate due to additional dewatering support by its offset well. Similar behaviour is observed in the production characteristics of an old producer when a new well is drilled in a nearby location. However, effects of interference are more dominant when a well stimulation activity (fracturing or re-fracturing) is carried out in an offset well. During stimulation activity, offset wells show an abnormal decline in gas rate and wellhead pressure due to fracking fluid (water) load up in the reservoir. Conversely, a significant positive impact is seen in gas rate of both wells after the well is put back on production due to improved water production rate in the stimulated well. Permeability calculations show that natural and artificial fractures dominate production behaviour of CBM wells. The study also presents results of various simulated geo-spatial well patterns. Furthermore, it is shown that planned interference at an early time with an economically designed well spacing can maximize the production NPV of an asset for an operator.
The optimal well spacing to maintain and/or increase gas production with the right amount of resources is critical for maximised returns. This result of this study can be used as foundation to help operators optimize multi-well pad and future infill well development program based on the assessment of short-term and long-term recovery targets.
Prosper & Cerberus Modelling for Efficient WBCOs in Artificial Lift Flowing Wells
Authors: Varma Nakul , Nagar Ankesh , Manish Kumar , Srivastav Pranay , Nekkanti Satish , Bohra Avinash , Srivastav Preyas 
Published: April 2019

Abstract
This paper describes simulation solution for CT(Coil Tubing) based WBCO in flowing ESP/Jet Pump wells for scale/polymer debris deposition removal prior to any treatment in well, such as – Formation stimulation, ESP treatment, etc. It also describes prediction for requirement of Surface Well Test spread support to assist Nitrogen assisted WBCO. The paper describes new way of simulation for CT WBCO job in artificially flowing wells to predict decreased Liquid rate from reservoir, CT pressure & friction pressure losses. The modelling is done in Prosper and Cerberus, the results of which are validated with surface well test and Multiphase flow meter data recorded during the jobs. The results observed were very close to modelled with a number of advantages such as – No loss returns, higher lifting velocities, prediction of increased/decreased reservoir liquid rate affecting Motor winding temperature in ESPs, no settling of debris, post job Increased Liquid gain from well, decreased tubing friction pressure loss
Utilizing Advanced Logs for Flow Unit Classification in Vertical Interference Test Modeling
Authors: Kumar Arvind , Gidwani Arjit , Singh Suraj , Wydiabhakti Tety , Mishra Siddhartha 
Published: April 2019

Abstract
Vertical Interference tests (VIT) are used to determine the hydraulic connectivity between the formation sand intervals. This paper showcases an innovative workflow of using the petrophysical log attributes to characterize a heterogeneous reservoir sand by making use of ANN (Artificial Neural Net) and SMLP (Stratigraphic Modified Lorentz) based rock typing techniques as well as image based advanced sand layer computation techniques.
Vertical interference test is either performed using a wireline formation testing tool with multiple flow probes deployed in a vertical sequence at desired depth points on the borehole wall or using a drill stem test configuration. Based on the test design, flow rates are changed using downhole pumps, which induces pressure transients in the formation. The measured pressure response is then compared with a numerical model to derive the reservoir parameters such as vertical permeability, hydraulic connectivity etc. The conventional way of model generation is to consider a section of reservoir sand as homogenous, which generally leads to over estimation or underestimation of vertical permeabilities. The technique proposed in this paper utilizes advanced logs such as image logs; magnetic resonance logs, water saturation and other advanced lithology logs to obey heterogeneity in the reservoir model by utilizing ANN/SMLP based rock-typing techniques. These rock types would be helpful in making a multi layer formation model for the VIT modeling and regression approach. The vertical interference test model is then used to determine the vertical permeability values for each of the individual rock types. The paper displays the workflow to utilize the rock type based layered formation model in vertical interference test modeling for a channel sand scenario.
A Blueprint to Manage Large Scale Unconventional Multistage Fracturing Operations: A Case Study of Raniganj CBM Field.
Authors: Kumar Anjani , Goswami Rishiraj 
Published: April 2019

Abstract
Unconventional oil and gas reservoirs are being explored significantly around the globe nowadays. The economical production of hydrocarbons from these unconventional oil and gas reservoirs like CBM requires very advanced and cost effective technologies. Hydraulic fracturing is such a technology which is being used in the oil and gas industry for many decades to create highly conductive channels in the formations having very low permeability values. Multistage hydraulic fracturing has been proved to be a great achievement in oil and gas industry to enhance the production from unconventional reservoirs. An effective hydraulic fracturing planning & execution is a key to achieve the expected results in terms of production from unconventional reservoirs such as tight gas, shale gas, coal bed methane or other very low permeability reservoirs.
Unconventional reservoirs such as Shale & CBM require large scale hydraulic fracturing operations, where multiple frac fleets, wire-line units, coiled tubing units; work-over rigs & ancillary services are mobilized. A scheduling software based project management approach was followed at CBM Raniganj for planning & modeling of operations. This paper aims to study how the operational resource deployed in Raniganj field for hydraulic fracturing was optimized in terms of time, cost & load for fracturing operations.
The approach of modeling & planning the hydraulic fracturing operations is based on project management & scheduling software. Assumptions were finalized based on experience. The loopholes, possible schedule slippages and other deterrents which could cause a lag in the hydro fracturing campaign aimed to pump over 1,600 frac jobs in CBM Raniganj field, over a period of 30 rig months, were identified clearly. The scope, time, budget & quality standards were clearly defined and a schedule was prepared with the help of the scheduling software to run the fleets in a clockwork manner. Activities like perforation, Acidizing, data fracturing, main fracturing, flowback, sand plug and finally sand cleanout were defined as series & simultaneous operation.