bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating Saturation Changes from 4D Seismic: A Case Study from Malay Basin
Authors: Pathak Ravi Kant , Bakar Rizal 
Published: May 2016

Abstract
4D seismic is increasingly being used for quantitative estimation of pressure and saturation changes related with production and injection operations (Landro, M., 2001, Christophe Ribeiro et al 2004, MacBeth C. et al, 2004, Cole S. et al 2002, etc). Variations in reservoir properties due to production and injection program induce changes in elastic reservoir properties which are manifested through 4D time shift and attribute anomaly.
In this paper, the workflow implemented for estimation of saturation changes from integrated analysis of well and 4D seismic dataset pertaining to the one field in the Malay basin is presented. The reservoir sands under study are deposited during Miocene age and are comprises of intertidal shales, siltstones, fluvio-tidal channel sandstones & minor coals.
Base 3D seismic data over the field was acquired in 1996 while Monitor 3D was acquired during 2006. Both dataset were processed implementing PSTM processing workflow using similar parameters. The NRMS value of Base and Monitor dataset was found to be 24 which is quite acceptable for quantitative analysis. Even though utmost care was taken during the processing to maintain the repeatability, there are still minor acquisition footprints observed in the Monitor & Base difference volume.
Correlation of Monitor & Base amplitude difference with Pressure Perturbation modeling (MacBeth 2003) suggests that the dominant 4D effect in the area of study is related with the saturation changes due to water injection and production. The 4D analysis workflow implemented for estimating Monitor saturation used Base reservoir model (saturation and porosity), Base & Monitor inversion volumes and ?Sw measured at wells. The workflow used the neural network inferences to predict Monitor Sw.
The Monitor saturation model obtained from the proposed workflow is seismically constrained in the inter-well & beyond the well regions. It supplements/supports existing dynamic model in identifying un- swept oil compartment and effective reservoir management.

Introduction
4D or Time Lapse seismic has established itself as a mature technology to support field development and reservoir management decisions. In Brown fields, 4D seismic is helping to locate bypassed oil, identify un-drained compartment, and optimize the infill drilling program leading to incremental recovery. As a reservoir surveillance tool, 4D provides information support in planning and implementing IOR/EOR operations. It provides information on fluid front position to support in optimizing the injector's locations.
Extending Gas Lift Systems Deeper into the Wellbore Using Capillary Through Tubing Services
Authors: Pate Brad , Stanley Rick , Nghi Nguyen Chinh 
Published: May 2016

Abstract

Introduction:
As wells with existing gas lift (GL) installations mature and reservoir pressures decline conventional GL systems often become less efficient. The lack of reservoir pressure makes it difficult to maintain a fluid level at a depth that allows the existing GL system to be effective. The cost of a work over remediation program to redesign and rerun the existing GL system can at times be considered uneconomical.

Application:
This innovative "Capillary Conveyed" through tubing system can be applied to most wellbores regardless of tubing size or depth.

Results, Observations, and Conclusions:
The first "Capillary Conveyed GL extension system installation was carried out for a major operator offshore Vietnam in January 2012. The existing GL system was no longer effective. The well was unable to flow and was shut in. After the installation the well took several days to unload and stabilize but then flowed continuously for 60 days at rates that exceeded the operator's expectations. After the initial 60 days production the well started to fluctuate and has since been put on a cyclical production regime. Cumulative production from the well from the date of the GL Extension System installation until May 2012 was 43,000 bbls oil. Project payout was estimated to be 4 days.

Significance of Subject Matter:
Wells that were once considered uneconomic due to cost, technical challenges and/or accessibility may now be re-evaluated as candidates for this new technology. This innovative through tubing solution has the potential to reinstate flow to wells where the existing GL system is no longer effective. Furthermore the system can be adapted to allow a new through tubing GL system to be introduced into a well that was completed without a gas lifting system.

Technical Contributions:
Advanced solutions utilizing "Capillary Technologies" provide cost effective production enhancement and improved reserves recovery while maintaining a relatively small foot print. This paper will review a case history where this "Capillary Conveyed" through tubing solution was successfully installed and reinstated flow in a well that was suffering from an inefficient GL system.

Field Overview:
Block 46/02 (Graphic 1) is located 205km offshore south of Ca Mau, the southernmost land fall of mainland Vietnam, and just north of the joint development area PM-3 CAA. The producing Kekwa oil and gas field in PM-3 CAA is located 15km to the southeast of Song Doc Area (SDA).
The Production Facilities Key Safe Technology of Gas Fields with High H2S/CO2 or High Pressure
Authors: He Jun , Yang Lina , Ba Xili , Wang Chunyan , Wang Qi 
Published: May 2016

Abstract
As the shortage of the energy, more and more gas fields with high H2S/CO2 or high pressure will be developed.
China's high sour gas fields are mainly concentrated in the northeastern Sichuan Basin, Daqing Xushen and Jilin. As the representative of high sour gas field Luojiazhai gas field, the H2S content is 9.5% ~11.5%, CO2 7% ~ 8%. In Changling gas field the CO2 content as high as 27%.
High pressure and high yield gas field are mainly concentrated in the Tarimu Basin Kela 2 gas field as the representative, single well yield is 105~140MMSCFD, wellhead flowing pressure up to 63.1MPa, corrosion is mainly from Cl- and CO2 the content of Cl- in produced water is up to 100667mg/l.
For these gas fields developed still on initial stages in China, there are a series of difficult problems of safe technology for production facilities. Aiming at these problems, the paper introduces CNPC's safe technology by research. The production facilities key safe technology includes process technology, material selection, setup of safety instrument, safety relief, safe distances.
Fracture Modelling Using Seismic Based Fracture Intensity Volume, a Case Study in Middle East
Authors: Hansheng Mu , Chuanxi Liu , Peng Li , Huihua Pang 
Published: May 2016

Abstract
In this paper, a case study in a fractured carbonate reservoir is presented to demonstrate the approach of fracture modeling using fracture intensity volume. Fracture information described from well data and fracture prediction data generated from pre-stack seismic data are both used to establish discrete fracture model.
FMI logs, mud losses, log interpretation results and production data are used to describe fracture characteristics on each well. Fractures are divided into 4 sets based on fracture scales, fracture dip and strike interpreted from FMI log. Fracture density logs for each set is generated separately, and each set of logs is used separately for fracture modeling. Seismic attribute of pre-stack azimuthal anisotropy is generated. This attribute volume is compared with FMI interpreted fracture density along wellbores for over 120 wells. The consistency of seismic attribute with well data is good for 90 per cent of wells. Hence the seismic attribute of pre-stack azimuthal anisotropy is used as fracture intensity volume for fracture prediction.
A DFN model is established for each set of fractures using FMI interpreted fracture density as hard data and the seismic based fracture intensity volume as constraining data. Fracture properties are calculated based on discrete fracture network and calibrated by well test analysis.

Introduction
The characterization of fracture reservoirs is one of the biggest challenges for geoscientists. It is attractive to us not only because of the contribution that fractured reservoirs have made to oil and gas production, but also because of the complexity of fracture system. Many attempts have been made in the past to find ways predicting fractures. Geomechanical researchers try to construct a fracture mechanical model from tectonic history (Mace et al., 2004). Geologists try to characterize fractures from facies type, porosity, and reservoir zonation. Geophyisists try to forecast fracture system by seismic properties, acoustic impedance, and spectral imaging attributes (Creties Jenkins et al., 2009). In this paper, an integrated approach is used for fracture prediction and fracture modelling. Fracture features including fracture inclination, azimuth and density are summerized in each zone from image logs. Some normal seismic attributes such as curvatures, ant-tracking volume, coherence volume, are calculated. What is more, a fracture intensity volume based on pre-stack anisotropy attributes calculated by FRS software is used. By using fracture density logs calculated from image logs, an integrated fracture intensity volume is interpolated with the combined seismic volume as a trend. This fracture intensity volume is used for creating Discrete Fracture Network.
Microfacies Analysis and Reservoir Characterisation of Late Cenomanian to Early Turonian Mishrif Reservoirs, Garraf Field, Iraq.
Authors: Ali F.H.M. , Ali Z. , Embong M.K. , Azmi A.A. 
Published: May 2016

Abstract
Garraf field is situated in southern Iraq, in Thi Qar Governorate. It was discovered in 1984, and proven to have hydrocarbon accumulation in Middle and Lower Mishrif by exploration and appraisals wells in Garraf. It has low relief gentle anticlinal structure aligned in NW-SE direction and has a dimension of 10km in width x 31 km in length. The Mishrif Formation were deposited in Mesopotamian Basin during the late Cenomanian to Early Turonian. Mishrif is a limestones formation with the approximate thickness of 200m.
Mishrif Formation is the major reservoir and contributes almost 70% of the field's total STOIIP. For the field development plan, a 3D subsurface model was developed for resource assessment and production prediction. However, due to limited wells availability in Garraf, the main challenges are modelling the reservoir continuity and heterogeneity throughout the field to ensure the resulted model represent the actual Mishrif Formation. For the last few years the understanding on the reservoirs were solely based on the regional information, however with the recently acquired conventional core from Mishrif formation and the availability of acoustic impedance from 3D seismic data give an opportunity to investigate the reservoirs in more details.
Information on the depositional environment and the facies distribution are very crucial during the facies and petrophysical modeling stages to ensure the resulted 3D model represent the actual subsurface condition. The objectives of this exercise are to integrate all the information and develop the depositional model and characterise the Mishrif reservoirs.

Procedures
All microfacies identified were from the core and thin sections and their reservoir characteristics were predicted based on the observation on the compositional and textural variables. Their specific depositional environment were modeled based on Wilson Microfacies Model (1975) and Standard Facies Belts (1975) with broad shelf. Each microfacies identified were grouped into several hydraulic units (HU) based on their flow zone indicators (FZI). Upon the calibration with the cored intervals, the FZIs were extrapolated to the uncored intervals. The rock typing (RT) were compared with the microfacies to ensure its vertically matched with each microfacies distribution. The hydraulic units were extrapolated to the uncored intervals and wells by using multi liner regression. The resulted RTs from this process were converted into microfacies based on observation from the cored wells, acoustic impedance, and regional settings.
Development of Detection Techniques for Monitoring and Optimising Biocide Dosing in Seawater Flooding Systems
Authors: Al-Moniee M.A. , Al-Abeedi F.N. , Koopal C. , Akmal N. , Sanders P.F. , van Veen S. 
Published: May 2016

Abstract
Anaerobic microorganisms which are frequently associated with corrosion fail Control of bacterial activity are posing major challenge in Saudi Arabia's massive seawater flooding systems. Biocides are used to control bacteria throughout the oil industry. A study to explore the feasibility to develop a detection technique for biocide batch treatments, preferably on-line and in real time, for their potential use in seawater flooding system network is described. Several methods to measure key components of the biocide composition were investigated in the initial stage. Three different techniques were explored during the feasibility phase study to detect and measure concentrations of biocide in seawater. This helped our plans for designing a sensor based on such detection techniques. The techniques explored were to monitor change in temperature, change in pH, and change in chromophore concentration (colorimetric) in the enzymatic reaction.
The investigated methods included the use of acetylcholine esterase, based on the pH change as a result of acetate formation, the production of reaction heat (thermal) or on the colorimetric detection of the chromophore concentration based on the conversion of acetylthiocholine in combination with a chromophore. It was found that the colorimetric system was the most versatile system to perform the measurement to be able to show the feasibility of the method in real sea water samples and to demonstrate the effects of the biocides on the measurement system.

1.0 Introduction
In water flooding systems, deoxygenated and filtered seawater is injected at strategic points along the periphery of the oil reservoir, displacing the oil and "pushing" it toward oil supply wells in the center of the formation. The technique enhances crude oil recovery substantially and allows for greater returns from the field.
The seawater flooding system in Saudi Arabia is the largest of its kind in the world. It is deoxygenated water and treated with various organic biocides mixtures. The short duration, high concentration batch biocide treatment is designed to prevent the growth of bacteria in the system, thereby minimizing biofouling, water quality deterioration and Microbially Influenced Corrosion (MIC).
Since the system's size is massive, it is very challenging to detect the arrival of a biocide slug treatment at the far water injection wells. Furthermore, quantification of biocide residual concentration in 'real time' at remote desert locations is not currently possible. Developing sensor technologies, which will quantify biocide residual concentrations hundreds of kilometers from the biocide injection location without manual sample collection and conventional wet chemistry analysis, is challenging.
Reef and Sand Reservoir Appraisal in Well-Absent Place: A Case Study in a Marine Area
Authors: Fan Chunyan , Song Yan , Jiang Zhenxue , Zhang Yuanyin 
Published: May 2016

Abstract
The inspiring but indeterminate scenery, that the reef extensively developed in our researching area with obvious bright-spot reflection and distinct seismic velocity drop could be filled by favorable gas, and the blurry reflections below the reef may correspond to periods of turbidity sand reservoir, needs to be more precisely and carefully appraised for further exploration with no hesitation. However, AVO inversion can not be efficiently applied in this unexploited place due to wells insufficiency, even though it is recognized as an excellent method for reservoir prediction and famous of its inverted real P-wave result and other abundant elastic attributes. To efficiently appraise the reservoir quality in this area, an advanced well-absent AVO inversion method, which constructs pseudo-wells according to the seismic interval velocity, amplitude and known message, is put forward and successfully applied in this paper. It is the first time to reasonably appraise the reservoir quality in our working area. The new well-absent inversion method could overcome the prediction obstacles in the early phase of exploration, and suitable for offshore exploration.
3D Petroleum System Modeling Study on Pearl River Mouth Basin (South China Sea)
Authors: Vitagliano Eleonora , Galimberti Roberto , Dalla Rosa Matilde , Gilardi Matteo 
Published: May 2016

Abstract
3D Petroleum System Modeling Study has been developed by using the Eni E&P Division internal package (e-simba™) in order to evaluate the petroleum potential of the Pearl River Mouth Basin, in the South China Sea.
Pearl River Mouth Basin is a Mesozoic-Cenozoic passive margin rift basin oriented NE-SW and parallel to the continental shelf. Within the Basin two main source rocks are recognised in the syn-rift succession: the organic levels of the Enping Formation, Oligocene in age and mainly terrestrial, and those of the Wenchang/Enping Formation, Oligocene/Eocene in age and mainly lacustrine.
Based on geochemical analysis of well data, the Enping source rock is modelled by using terrestrial kerogen type, TOC 1%, HI 250 mgHC/gTOC, 100 m of thickness and kinetics from analogue of Mahakam Delta. The Wenchang/Enping source rock is modelled by using lacustrine kerogen type, TOC 4%, HI 600 mgHC/gTOC, 100 m of thickness and kinetics from analogue of Green River.
Thermal data coming from wells and confirmed by literature suggest an average geothermal gradient of 35°C/km. The heat flow values at Present time match with well data. The creation of heat flow map was done by using a geostatistical approach, kriging with external drift method - software ISATIS, and by considering the correlation between the calibrated heat flow value at single well and the geological trend. Over the study area the heat flow trend correlates both with seismic and magnetic basement.
The results of thermal model integrated with geochemical well data (CO2 and gas maturity) show that the heating better correlates with seismic basement and allow to define the positioning of the organic matter level. A terrestrial source rock can be located in the shallower part of the Eocene/Oligocene sequence while a lacustrine one can be localised in the depocentral area at the base of the same sequence.
Broadband Processing of Conventional Marine Streamer Seismic Data
Authors: Zhou Zhengzheng , Xu Bing 
Published: May 2016

Abstract
We have developed WiBand, a de-ghosting and broadband processing method that can be applied to conventional streamer data acquired with single component streamers. We recorded, over one sail line, multi-streamer data with the streamers towed at different depths, obtaining data over multiple subsurface lines (tracks) parallel to one another. We apply WiBand to each track independently to remove the effects of the source and receiver ghosts. We compare the WiBand results from a deep tow track to conventionally processed result from a shallow tow track to validate the phase fidelity of the de-ghosting process. The results lead us to conclude that WiBand correctly removes the ghosts and recovers broadband data from deep tow streamer data.

Introduction
The vast majority of marine seismic data are acquired with conventional towed streamer cables which are equipped only with hydrophones and are all towed essentially at the same constant depth for any single survey. The receiver ghost zeros out the spectral response of the recorded data at notch frequencies equal to any integer divided by the ghost delay time, limiting both the top end of the usable spectrum as well as attenuating the low frequency response. The source ghost has a similar effect. The combined effect of the ghosts results in greatly reduced resolution in the subsurface image. A conventional "solution" for this problem is to tow the sources and streamers shallow (at less than 7m of depth below the surface) to obtain higher frequencies, at the expense of attenuating low frequencies and exposing the sensors to a noisier environment near the sea surface.
There are currently several acquisition methods that can mitigate or remove the effects of the ghosts and obtain broadband seismic images (Carlson, 2007, Posthumus, 1993, Soubaras, 2010). These methods require nonconventional data acquisition, either with streamers equipped with multi-component sensors, or with streamers configured in unconventional geometries such as over-and-under or slanted configurations. Such methods are not applicable to conventional streamer data.
We have developed an effective broadband processing method based on a new de-ghosting technique. It can remove most of the ghost effects from conventional streamer data. In this paper we will refer to this method as WiBand. This method is designed to address both the amplitude attenuation and the phase distortion introduced by the ghosts to obtain nearly flat spectral response in the typical range of 4Hz to 150Hz, as well as a compact, well focused seismic wavelet. In order to validate our method, we carried out an experiment where multiple streamers were towed at different depths, and evaluated the phase reconstruction fidelity of the algorithm by comparing the WiBand result from the deep tow data with the standard processing result from the shallow tow data.
Remote Real-Time Analysis - A Game Changer for Remote Operation Centers
Authors: Saeverhagen Erland , Thorsen Arve , Dagestad Jan Ove , Spanovic Nic , Cannon Katherine 
Published: May 2016

Abstract
Drilling, completion, production and general surveillance are all areas that benefit greatly from remote real-time analysis, providing significant value to operators through proactive, rather than reactive, responses to challenges during day-to-day operation. Several different disciplines that previously operated separately are today integrated in their work; both in the field and remotely, continual monitoring and remote data analysis includes and integrates areas such as drilling optimization, pressure management, pore-pressure predictions, and wellbore stability. Software models that utilize case-based reasoning and physics, together with real-time drilling and well data, enable immediate situational analysis and trend monitoring. Advice today is provided remotely, requiring fewer personnel at a rig site. However, there are several challenges to remote services with many of these elated to communications issues, a fear of job loss and working outside a comfort zone. What is considered an important development goal for a business might be regarded as a threat for an individual, leading to reduced development within remote services. This paper presents the consequences of an ever-more automated oil field - benefits, challenges and a future outlook.