bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Analysis on Isochronal Facies-Controlled Pre-Stack Seismic Inversion Prediction of Tight Sandstone Reservoir- A Case of Fuyu Formation in Zhaoyuan Area in North Songliao Basin, China
Authors: Chen Meiyi , Ji Qingsheng , Chen Shoutian , Qin Longpu , Cong Peihong 
Published: April 2019

Abstract
Based on the seismic prediction difficulties of the tight sandstone reservoir in Fuyu formation in Zhaoyuan area, single-well sequence division and connecting-well sub-layer correlation are carried out according to logging and lithologic data, and short-cycle interface position is calibrated precisely after a mutual calibration of logging and seismic data. Horizon tracing in the whole area is also carried out to build high-frequency isochronous stratigraphic framework. On this basis, the log facies modes and the sedimentary facies of the short-cycles under a high-frequency isochronous stratigraphic framework are analyzed in the target area, sand-body geometric scale parameters and their relations and sand-body development degree are calculated out, and a sand-body geological model is also built out. According to the seismic data and layer-by-layer geological model of sand bodies, a spatial distribution probability model of facies-controlled sand bodies is built out, which is used to constrain the pre-stack seismic data in facies-controlled inversion calculation. Based on the results of facies-controlled inversion, the tight sandstone prediction is carried out. Finally, a method of isochronal facies-controlled pre-stack seismic inversion prediction of tight sandstone reservoir is formed and it realizes the effective prediction of superimposed sand bodies in target area. Compared with actual drilling results, the sandstone of more than 2m has clear depiction and the sandstone of between 1-2m also has response, which indicates that this method is feasible and practicable.
Investigation of Anhydrite Dissolution as a Potential Low Salinity Waterflooding Mechanism Using Carbonate Reservoir Rocks
Authors: Uetani Takaaki , Kaido Hiromi , Yonebayashi Hideharu 
Published: April 2019

AbstractMany mechanisms have been proposed for low salinity waterflooding enhanced oil recovery (EOR) in carbonate rocks over the last decade, and they are still in debate. One suggested mechanism is the dissolution of anhydrite (CaSO4) mineral from a rock material, which generates sulfate ions in-situ, and subsequently acts as a wettability modifier chemically. Another suggested mechanism is the increase in permeability due to mineral dissolution. Primary objective of this work was to verify whether dissolution of anhydrite could be the key low salinity waterflooding EOR mechanism.Spontaneous imbibition tests were conducted using six rock samples from two carbonate oil reservoirs. The first reservoir rock contains anhydrite, while the second reservoir does not contain anhydrite. If anhydrite dissolution is the key mechanism, then the amount of increased oil recovery due to low salinity brine should correlate with the amount of anhydrite dissolved from the rock. Our experimental results, however, did not suggest such a relationship. Hence, anhydrite dissolution was considered unlikely as the key mechanism of low salinity EOR for the crude-oil, brine and rock (COBR) system used in this study.
Resolving Shallow Reef Effect with New Water Layer Demultiple Method and Diving Wave Tomography: A Case Study from South China Sea
Authors: He Jiao , Li Rong , Yang Sherman , Liu Zheng , Zhu Ming 
Published: April 2019

Abstract
The survey with shallow reef is located at the Pearl River Mouth Basin of South China sea. Water depth is around 100 meters but variable across the survey. The shallow reef is in the middle of survey. It is about 14km width and 10km length spatial size. With such huge spatial size, it had posed big challenges to subsurface reservoir imaging.
Firstly, the variable water bottom generates complicated water layer related multiples, especially at the shallow reef area. Meanwhile, with limited near offset information in the legacy NAZ data, accurate water layer multiple model is very difficult to predict with conventional methods.
Secondly, the shallow reef mainly composed of carbonates, which have higher velocity compared to surrounding sediments. This high velocity carbonates thus cause severe distortion to the wave field propagated through and severely distorted the underlying reflections. Without correct imaging of reef at shallow, little confidence can be brought to deeper structures imaging, and interpretation.
The Fracture Network Inversion Based on Gas Production Profile
Authors: Mi Lidong , Yan Bicheng , Liu Qianjun , Ren Zongxiao 
Published: April 2019

Abstract
The fracture description plays an important role in shale gas well production performance prediction, late production refracturing design and infill well trajectory design. Based on the development and geological parameters of Fuling shale gas field, the enhanced discrete fracture network (EDFN) numerical simulator is used to study the influence of fracture length, total fracture length, stage spacing and relative position of fractures on the contribution ratio of fracture stage. According to the relationship among JY46-3HF gas production profile, gas production contribution ratio and fracture characteristic parameters, a fracture network model is established. The simulation results of gas production contribution ratio of each fracture stage are highly consistent with the measured data. The research results show that: the contribution ratio of gas production in each fracture stage is positively related to the total cumulative fracture length, and the fracture spacing and relative position of fractures affect the contribution ratio of fracture stage to shale gas well by the size of matrix area controlled by fracture.
Monte Carlo Optimization for Site Selection of Process Facilities in Oilfields Considering Environment
Authors: Wang Bohong , Liao Qi , Zheng Jianqin , Yuan Meng , Zhang Haoran , Liang Yongtu 
Published: April 2019

Abstract
The site selection of the facilities in oilfields is one of the important issues for surface engineers. In the progressive development of oilfields, new wells are explored and developed, and new process facilities (PFs) should be constructed to gather and process the fluid from these new wells. The emission of the PFs will affect the surrounding environment, including water sources, forests, and human settlements. Thus, the environment should be considered as one of the key aspects in the design process of facilities. Different locations of facilities in the oilfields will affect both the construction cost and environmental cost. Thus, a balance has to be found. In addition, the uncertainty of production rate of well fluid poses a great challenge to this problem. To solve the above problem, this paper provides a systematic methodology.
The objective function consists two parts: construction costs and environmental cost. The solving algorithm has involved three layers of looping programming to calculate the value of objective function. First the weather conditions are generated by the Monte Carlo method, then the second loop is for the study areas, and the third loop is for the new facilities locations. After all the loops of iterations are completed, the objective functions are calculated, and the influence of the environment can be evaluated. Finally, the best solution can be obtained.
The effectiveness of the proposed method is demonstrated through a design problem in an oilfield. The candidate locations for PFs are previously determined, and the optimal construction plan is solved by our method. The quantitative influence on the environment to these candidate locations can be evaluated. After determining the coefficient of the construction cost and the environmental cost, the best locations for the process facilities with the lowest total cost can be determined.
A multi-objective model for the site selection of process facilities in oilfields is proposed, which has not been done by existing literatures. The construction cost and surrounding environment are both considered in the model. This work has the potential to serve as a decision-support tool for surface engineers in oilfields.
Study on the Phase Equilibrium of Gas Hydrate Based on Main-Branch Pipe Confluence Model
Authors: Deng Song , Liu Yali , Wei Xia , Tao Lei , He Yanfeng 
Published: April 2019

Abstract
Phase change, a major factor that restricts the development of gas hydrate, is likely to cause blockage in well completion section (sieve section – wellbore lifting section), thus resulting in the engineering losses. In view of the defects in the previous studies on the confluence mechanism of completion section of gas hydrate pressure drop method mining under openhole completion technology, the flow of gas hydrate in the well completion section was simplified as the Main-Branch pipe confluence model in this paper. Firstly, a physical model was established. On the basis of the energy conservation law and the Peng-Robinson equation, the temperature and pressure coupling model was also derived. Then, the Fluent software was used to simulate the temperature gradient and pressure gradient changes in the Main-Branch model. The gas hydrate phase diagram and P-T environment under different velocity were obtained. Finally, the contrast analysis between theoretical model and numerical simulation was carried out and the established model was verified. Through the study of this paper, it is possible to prevent blockage of the well completion section by means of depressurization, which can provide theoretical guidance for the control of pressure drop when gas hydrate is extracted by depressurization. It is important for the exploitation and continuous production of gas hydrate in the later stage.
Development of a New Parallel Polymer Flooding Simulator for Conventional and Naturally Fractured Reservoirs
Authors: Liu Hui , Chen Zhangxin , Shen Lihua , Zhong He , Liu Huaqing , Yang Bo , Ji Dongqi , Zhu Zhouyuan , Zhan Jie 
Published: April 2019

Abstract
This paper deals with the development of our parallel reservoir simulator that is designed for giant reservoir models. It considers oil, water and polymer, and a reservoir can be a conventional reservoir without fractures or a naturally fractured reservoir. For polymer flooding, the simulator can model polymer retention, adsorption, an aqueous phase permeability reduction and viscosity increase, and an inaccessible pore volume. Here fractures are modeled by the dual porosity and dual permeability method. The finite difference (volume) method is applied to discretize the model, upstream techniques are employed to deal with rock-fluid properties, and the fully implicit method in time is applied. The linear systems from the Newton method are ill-conditioned and a scalable CPR-type preconditioner is employed to accelerate the solution of these linear systems. The computed results are compared with those from commercial simulators, and they match very well. The scalability of the simulator is good.
Novel Non-Damaging Hybrid System for Sand Consolidation Application
Authors: George C. Shoy , Nguyen D. Philip , Patil Prajakta 
Published: April 2019

Abstract
Sand consolidation technology has evolved in recent years to accommodate more rigorous requirements with regards to health and safety, operations, downhole conditions, and high production flow rates. Because of stricter environmental requirements, most operators prefer to apply aqueous-based consolidation treatment fluids instead of solvent-based fluids. However, clay-laden formations can be sensitive to water, and thus the use of aqueous-based treatment fluids is problematic in these formations, especially in those with high clay contents.
This paper presents an aqueous, silane-based resin system for stabilizing and strengthening unconsolidated formation sand surrounding a wellbore. The chemistry of this silane-based treatment fluid was determined to effectively treat large surface areas of formations containing high clay concentrations, while providing high bonding strength between sand grains without plugging their intergrain pore spaces to retain the high permeability of the treated formation. Rather than depending on complete consolidation of formation materials surrounding the wellbore for successful sand control, the new resin enables agglomeration of formation particulates to form aggregates or clusters, thus helping to prevent them from passing through slotted liners or sand screens.
Rock mechanics evaluation of clay-laden sands treated with this new resin system shows that they possess elastic properties and survive the effects of stress cyclic loading. Scanning electron micrographs (SEMs) of the consolidated core material clearly reveal the formation of a porous network of fines and sand, causing little damage to the porosity and permeability of the treated formation. This new resin system provides an alternative to conventional sand control completion in lower quality reservoirs, as well as an effective through-tubing completion alternative. The treatment helps ensure the effectiveness and longevity of standalone screens, thus providing operators with an economical means for well completion.
A Holistic Approach to Life Extension of Fixed Offshore Platforms in Malaysian Waters
Authors: Ng Sok Mooi , Khan Riaz , Isnadi Biramarta , Lee Luong Ann , Saminal Siti Nurshamshinazzatulbalqis 
Published: April 2019

Abstract
The objective of this paper is to share the holistic approach to managing aging fleet for offshore fixed steel structures. PETRONAS is currently operating a fleet of more than 200 fixed offshore structures in Malaysian water. More than half of it has exceeded the original design life. With enhanced oil recovery and other developing technologies, offshore platforms often than not are required to continue operating beyond its original design life.
A holistic approach for life extension of fixed offshore structures are being developed to ensure safe operations of the facilities. PETRONAS has started SIM journey since 2007. The approach of Data, Evaluation, Strategy and Programme in line with API RP 2SIM set the basis for managing the integrity of the offshore fleet. An integrated solution was developed to manage both topsides and substructures. The Structural Integrity Compliance System (SICS) which houses the integrity management of topsides deteriorations to prioritize resources through risk based anomalies management. Risk based underwater inspection also formed part of the solutions, addressing mainly extreme storm in the region. Other Major Accidental Hazards (MAHs) risk ranking included in SICS are vessel collision and seismic. Management of facilities with minimal redundancy such as guyed wire monopod is addressed through time based inspection. A regional hazard curve is also developed to ensure the facilities are meeting the acceptance criteria set forth by the industry.
Besides aging, other integrity triggers including shallow gas and subsidence required a different scheme in managing the integrity of the facilities, primarily addressed through a comprehensive monitoring programme.
There is no one size fit all recipe in managing the aged platforms for life extension. The data plays a crucial role in ensuring the right methodology is deployed in support of digitalization and data driven decision making. Implementation of the system is proven to be reliable in ensuring the offshore fixed structures are intact to support safe and continuous operations to the operator in a cost optimum manner. The data analytics help to enhance the predictive model to optimize the inspection and maintenance programme.
Strong ownership and commitment of the structural integrity engineers in ensuring the data integrity maintain the challenge in sustainability of the system and provide reliable source for data driven decision making to the operator.
Category: Operational Excellence (136 - Managing Aging Facilities)
Using Deep Kalman Filter to Predict Drilling Time Series
Authors: Yu Yingwei , Liu Qiuhua , Chambon Sylvain , Hamzah Mohammad 
Published: April 2019

Abstract
Drilling automation design can benefit from simulated data. A drilling timeseries simulator can enrich the dataset for testing, and enable the inference of the drilling states in real time; however, conventional simulators based on simplified physical models usually lack the vivid patterns seen in real datasets. In this paper, we present a solution that uses a deep neural network-based Kalman filter. This system learns from real data, characterizes the different drilling responses, and conditions the data.
The dynamics of a rig drilling system can be modeled as G(P, E, U) → Z, where P is the plant of the rig mechanical system, E the environment (i.e., the earth, formations, etc.), U the rig controls (e.g., the top drive RPM, the flow rate, etc.), and Z the measurement (e.g., the hookload). The dynamics can be described with a non-linear Kalman filter. The Kalman filter contains components of internal states, inputs, and measurements, and transfer functions for the internal states, inputs, and measurements. We model these transfer functions with deep neural networks, and solve these transfer functions by training with real data. The implemented deep neural network model contains components of convolutional neural network layers, long short-term memory layers, and deconvolutional layers.
We trained the neural network with a real drilling datasets. Two experiments are presented. In the first one, the inputs are time-windowed multiple channels of RPM, block position, slip status, flow rate, and weight on bit, and the outputs are the response channels of torque, ROP, hookload, standpipe pressure, etc. The training accuracy achieved 99.5% after 50 epochs. In the second experiment, the network is trained to predict 16 rig states.
In summary, the introduced deep neural network is a generic model for generating simulated time series and classification tasks.
The Application of Cyclone Desorption Technology for OBM Drill Cuttings Disposal
Authors: Wu Jiwei , Pan Jiake , Wang Hualin , Wang Lixiang , Lan Xiaoping , Yang Lijie , Liu Wenjin 
Published: April 2019

With the flourishing shale gas exploitation produces more oil based mud (OBM) drill cuttings, the hard-to-treat hazardous waste burden the local environment heavily. However, the problems of high energy consumption, high treating cost and high secondary contamination risk still remain unsolved for mainstream technologies such as thermal distillation, incineration and chemical extraction. Therefore, a new method and device based on cyclone desorption of high speed self-rotation to dispose of OBM drill cuttings are put forward to overcome the challenge.The working process includes: viscosity reduction in heated gas; cyclone deoiling; condensation and recycling of exhaust; separation of oil and water in coalescer. It is found that the self-rotation speed of solid particles in a 3-dimensional rotating turbulent flow field of cyclone is as high as 2,000 to 6,000 rad/s which coexists with revolution speed of 20 to 300 rpm. The remarkable pulsing centrifuge forces in the self-rotation and revolution coupling motion can enhance the desorption process of the oil so as to accomplish the separation and enrichment of oil and solid phase, and deep removal of organics from OBM drill cuttings.It turned out that the deoiling efficiency of OBM drill cuttings, a sample from Chongqing shale gas field, increased as the processing time longer and, to be exact, after 2.1 seconds the oil content fell from 17.9% to 0.16% which is about a half of the maximum allowable content of petroleum in pollutants, 0.3%, in GB 4284-84 "Control Standards for Pollutants in Agricultural Sludge".In general, the innovation of cyclone desorption of high speed self-rotation is the pulsing centrifuge force of self-rotation and revolution coupling motion, so it's free of chemical addition and high heating temperature. Therefore, the application of cyclone desorption of high speed self-rotation for OBM drill cuttings disposal is expected to lower treatment cost, enhance processing effect, and finally improve the environment of shale gas exploitation area and contribute to energy development.
General Guidelines for Batch Treatments of Polylactic Acid for Diversion in Multistage Matrix Acidizing Treatments
Authors: Shirley Robert , Hill A. Dan 
Published: April 2019

Abstract
In the last decade, there have been several publications describing the use of Polylactic Acid (PLA) as a diverting agent in multistage matrix acidizing treatments. The solid polyester is particularly useful as a diverting agent because it hydrolyzes in the presence of heat and water leaving no residue in the formation, negating the need for any clean-up fluids. Most of the publications thus far focus on characterizing the physical and chemical attributes of the diverter and demonstrating its effectiveness in field trials. This paper develops some general guidelines for the application of PLA diversion in multistage matrix acidizing treatments by conducting sensitivity analysis on the design parameters of three field cases.
To carry out these sensitivity analyses, an empirically derived model that describes how PLA creates a skin factor during multistage matrix acidizing treatments is incorporated in a near wellbore simulator. This simulator also tracks the fluid interfaces, models the transient reservoir and wellbore flow, and calculates the wormhole propagation rate and a number of completion skin factors. The design parameters that will be investigated include whether PLA should be sized to enter the wormhole or to bridge at the sand face, diverter concentration, specific cake resistance, the number of diverter stages, and the total volume of acid pumped. The efficiency of the diversion treatments will be compared based on the overall final skin factor and uniformity of the skin profile along the well.
This paper reveals that PLA is significantly more effective in creating a uniform skin profile if it is designed to bridge the wormhole openings rather than to enter them. It is also shown that increasing the diverter concentration or using a diverter with a higher specific cake resistance can create a more uniform skin profile but there is an inverse relationship with the overall skin factor. It is shown that using the same volume of the diverter in a few diverter stages is better than pumping all of the diverter at once, but that there is a limit where using a larger number of stages does not add any benefit. The study highlights the need to fully stimulate the high permeability zones before pumping the PLA, and finally, it suggests that the total volume of acid used should be higher when PLA diversion is used to offset the adverse effects on the overall skin factor.