bluuebunny/crossref_metadata_2025_split huggingface dataset:
How to Integrate Wireline Formation Tester, Logs, Core and Well Test Data to Get Hydraulic Flow Unit Permeability’s: Application to Algeria Gas Field
Authors: Elarouci Fethi , Mokrani Nabil , El Djoudi Salim Mouici , Hill Peter 
Published: July 2010

Abstract
Reservoirs in Algeria typically contain multiple rock types from different facies depositional systems, and their identification and their evaluation in some areas, is becoming more challenging.
It’s not easy to get a unique permeability value for specific flow-unit without combining different formation evaluation disciplines. Logs, cores and Well tests data, provide information not only of different kinds of permeability but also at different scale measurements.
The presented methodology is a case study of an integrated work performed during an exploration and appraisal stage in a gas field in Algeria.
The integration technique steps consisted of:
Identifying facies and hydraulic units from core data analysis Computing permeability curve in the entire reservoir including the non-cored zones by combining logs and porosity/permeability relationship of each hydraulic flow unit. Analyzing well testing transient pressures and estimating flow capacity. Computing permeability at the identified flow-unit scale by the analysis of wireline formation tester data using its inflatable straddle packer configuration.
The synthetic permeability curve showed a good correlation between core data and predicted values. A thickness that is actively contributing to the flow has been identified. Permeability values at the flow-unit scale were then computed.
The obtained results from the integrated technique provide accurate dynamic characteristics in a gas-bearing formation and constrain the producibility knowledge of a reservoir.
Testing and History Matching ES-SAGD (Using Hexane)
Authors: Ayodele Oluropo Rufus , Nasr Tawfik N. , Ivory John , Beaulieu Gilles , Heck Gord 
Published: July 2010

Abstract
For the first time, we present in public domain, experimental and history-matched results of 2D scaled laboratory testing of ES-SAGD with hexane as the co-injected solvent. Experimental results of ES-SAGD (with hexane) were also compared with the equivalent SAGD. The 2 experiments, which were conducted at the Alberta Research Council's Thermal Gravity laboratory, are 2-D high pressure/high temperature experiments and were conducted at 2100 kPag +/− 50 kPag. The comparison of ES-SAGD and SAGD experiments shows that ES-SAGD using hexane performed better than an equivalent SAGD experiment. The energy consumption per unit oil recovered for ES-SAGD was lower than that of SAGD (11.5% less). The average oil recovery within the first 500 minutes (i.e. 11.3 years at field-scale) for the ES-SAGD process was also much higher (~10.93% higher). The ES-SAGD result was history-matched with a commercial reservoir simulator (CMG STARS). The history-matched ES-SAGD experiment gave satisfactory results in terms of oil production rates, cumulative oil production, and temperature distributions. The results presented in the paper provide data that can be scaled to field and assist in the design, optimization and parameter selection when ES-SAGD (with hexane or a pseudo-hexane solvents mixture) is considered as a recovery technology. Multi-pattern simulations based on history-matched data of a single well pair (pattern) show that multi-well pair (pattern) simulations can provide a suitable approximate analog for multi-pattern experiments, which can be scaled and used for planning and optimizing a pilot or a small-scale commercial project.
An Inequality-Constrained Extended Kalman Filter for Continual Forecasting of Interwell Connectivities in Waterfloods
Authors: Zhai Daoyuan , Mendel Jerry M. 
Published: July 2010

Abstract
Liu, et al [5], [6] developed an Extended Kalman Filter (EKF) for a producer-centric reservoir modeled as a collection of continuous-time impulse responses that convert injection rates of all contributing injectors into a production rate. Their EKF model estimates two parameters for each producer-injector pair, which can be used to compute an Injector-Producer-Relationship (IPR) value. Zhai, et al [18] then modified their EKF model to directly estimate the square-root of the IPR value for each producer-injector pair, and developed a set of heuristic strategies for implementing the EKF model on much more complicated and noisy real field-data. In both works, the IPR values of a whole field are obtained by the EKF processing of each producer model independently; however, an important type of injector-centric constraint needs to be imposed across producer-centric models, namely, the sum of the IPR values of each injector has to be less than or equal to one. Unfortunately, it is not possible to impose such constraints using the current EKF structure.
Recently, Simon, et al [12]-[14] and Yang and Blasch [16] have shown how to incorporate equality and inequality constraints into the structure of a Kalman filter. This paper extends their linearly constrained Kalman Filter to the producer-centric EKF model. For the first time, all of the producer-centric models are coupled together by constraint coupling due to the constraint on the sum of the IPRs. This paper then uses a mini-simulated oilfield to show how unconstrained EKF processing can cause the sum of the IPRs to be greater than one; and, demonstrates, using both simulated and real oilfield data, how the constrained EKF can be used to couple the whole field thereby obtaining the correct IPR values.
Unlocking Potential From a Marginal Clastic Field in Oman
Authors: Al-Harrasi A.. , Al-Salhi M.. , Rathore Y.. , Bareg S.. , Bhatti K.. , Shukaili S.. 
Published: July 2010

Abstract
The remotely located Z field has no testing, processing or gathering facilities and production is currently processed at the closest field production station 20 km away. The Z field consists of multiple stacked Permian clastic reservoirs in a low relief three way dip-closed structure bounded to the east by a north northeast–south southwest trending fault. Few other faults exist in the field and the identified faults most likely act as baffles to flow. Hydrocarbons are trapped in the marginal marine Middle Gharif (MG3) reservoir unit and in the younger MG2 fluvial sand bodies. The fluid properties range from high gravity crude oil in the MG3 (45°API) to volatile oils in MG2. This high GOR fluid limited the artificial lift options. The initial reservoir pressure is 26 bar in the MG3 with a bubble point pressure of 22.2 bar.
Despite challenges and uncertainties, the Z field was successfully developed by an optimised IOR method utilising onsite waterflood development to maximise field NPV. Artificial lift options are continuously modelled to find the optimum lift mechanism (mix of free flowing and ESP wells). The field production stabilised since 20005 when water injection was implemented to avoid drawdown below bubble point.
Integrated field reviews and analysis lead to a better understanding of reservoir performance. The interference tests and transient analyses performed for both injectors and producers provided insight into the field performance. These reviews led to successful drilling in 2009 with an additional upside potential of doupling the field production.
The plan for this field is to further develop the MG3 with a water flood utilising streamline simulation and start the MG2 appraisal development since more well control points are now available.
Production Enhancement via Scale Removal in Nar Formation
Authors: Farrokhrouz M.. , Asef M. R. 
Published: July 2010

Abstract
High rate of gas production from a well may result in brine production from different formations. When incompatible brines with different degree of saturation are mixed, precipitation of the salt could plug the well. Evaluation of openhole section was performed on a well in a gas field in Iran to check the well productivity. Unexpectedly, the tool was blocked a few feet below the casing shoe indicating the reason for production reduction. Attempts to remove scale deposition were unsuccessful and motivated comprehensive review of potential reasons to identify the properties of precipitated mineral. Crystal overgrowth of sulfate salt was considered to be the most likely mechanism, because the production zone was located in Nar formation which was mainly composed of anhydrite.
A comprehensive investigation was conducted in order to verify the type of bridged section. In-situ chemical conditions were identified based on general geological data, rock formation, rock types and brine sampling in reservoir rock. In such case at each production rate a different volume of brine was observed. Therefore, aqueous environment, ions and other in-situ conditions were modeled. The model was constructed using dynamic simulation software. Based on this model salt precipitation was reproduced confirming in-situ scaling problem. A prototype was developed to disperse this material based on previous laboratory experiments. Quantity and volume of additives for well treatment and scale removal were calculated accordingly. A scheduled production plan was proposed to identify the potential problems and appropriate strategy at each production rate. Study of this case in terms of site investigation, problem definition, and solution identification could accumulate valuable knowledge to quickly solve the problems in similar cases. In addition, presented simulation method would be the most economical method for scaling prevention and production optimization.
Time-lapse Seismic Study of South China Sea
Authors: Yuhong Xie , Zhihong Chen , Jiaxiong Zhou , Aihua Gou , Yuecheng Sun , Weiwei Liu 
Published: July 2010

Abstract
Time-lapse seismic study of South China Sea was begun from 2001. Two time-lapse seismic projects(YC13-1 and DF1-1Gas Field) had been done before June 2009. The paper tries to introduce the success and lessons of these projects, which include project feasibility study, core measurement, data processing and integrated interpretation.
Associative Polymer Usage as Stimulation Diversion System for Multilayered Reservoirs: Case Study of its Effectiveness for Stimulating Tight Layers in Khuff Carbonate Formation from Saudi Arabia's Ghawar Field
Authors: Al-Harbi Abdulaziz , Al-Malki Bandar , Al-Haddad H.M. , Vielma Jose 
Published: July 2010

Abstract
Acid fracturing as stimulation treatment for lower permeability multilayered reservoirs has been extensively used for carbonate formations around the world. For multilayered reservoirs, the success of stimulation is highly dependent on the fracture capability to connect the layers, fluid leak-off, fracture geometry and stimulation fluid properties. In Khuff carbonate reservoir from Ghawar Field, the heterogeneous nature of the multilayered formation, temperature, layers separation and especially wellbore deviation along the interval to be stimulated present additional technical challenges for fracturing stimulation and all of them has been addressed by incorporating Associative Polymer blends as a separate step to assure an effective fracturing stimulation fluid diversion.
The paper will show a case study for gas well in Ghawar field where an effective diversion technique with Associative Polymers was used successfully in fracturing treatments which resulted in enhancing more of tight layers contribution and increased total productivity by more than an order of magnitude. Associative Polymer (AP) blended in an innovative way forming, a solids or fibers free non-reactive water base system. The new diversion system was successfully used in several gas wells completed in Khuff carbonate reservoir where clear diversion and acid reaction signatures have been implied by surface and bottom-hole pressure (BHP) data recorded during the entire treatments. Production increases in addition to Pressure Build-up (PBU) and Production Logging corroborated the flow contribution from all the perforated intervals included tight layers, which contrasts with offset producers previously treated with other types of diverting agents.
The paper will present for the first time the treatment design and benefits of AP blend diverting agent usage for acid fracturing stimulations. A case history where the wellbore orientation is 45 degree is going to be presented and discussed in detail. Field case shows that the wellbore deviation was not a limitation for the effective stimulation and for the AP blend system to work. In addition, this paper will provide some guidelines for potential use of this diverting agent and candidate selection, treatment design, and execution.
Tectonic Escape (Indentation) in Central Saudi Arabia, Possibility and Exploration Potential
Authors: Khalil Mesbah , Muzaiyen Emad , Hmoud Khalid , Ismail Luay 
Published: July 2010

Abstract
Tectonic analysis indicates a high possibility of tectonic escape (P. Tapponnier and others, 1982, Armijo, R and others, 1986) structures in central Saudi Arabia that could bear significant hydrocarbon exploration potential. This study aims to introduce a new tectonic model that explains several surface and subsurface newly mapped structures in central Saudi Arabia. Potential fields, seismic and surface geology data are integrated to accomplish this study.
Basement terrane analysis of the Arabian shield and its eastern continuation beneath the sedimentary basin indicates the general north-south orientation with differences in width and composition. It shows that the maximum crust thickness is in the middle of the outcropping shield with a promontory extending 200 km toward east in subsurface (Central Arabian Arch) where Triassic (Khuff) marine carbonates overlay the basement directly. The crust shows gradual thinning eastward from this promontory till the offshore Arabian Gulf. Some terranes show wedging-out and others show narrowing against the eastern side of the basement outcrops. This pattern suggests the tectonic escape of the wedging out and narrowing terranes against the competent Afif terrane since the InfraCambrian accretion of Arabia. The terrane accretion occurred by westerly driven terranes collided against the thick promontory of the Afif terrane causing dispersion toward south and north through east-west accommodation zones. Long segments of unusual east-west surface structures (faults and strike of strata) over the boundaries of the subsurface basement promontory from north and south are thought to be a dragging of the dispersed terrane fragments at the promontory boundaries. West of these east-west zones, deformation is concentrated at the north-south terranes with curved hard link transfer zones. This InfraCambrian tectonic setting is believed to have been reactivated during Phanerozoic tectonic phases to express its escape tectonics pattern further-up till outcrops. Re-distribution of the Phanerozoic stresses at that inherited basement fabric controlled the geometry of the sub-basins and their filling during extension phases. It controlled also the preferable locations of structural positive inversion during compression phases to form the fault related fold traps. This approach explains the diversity of structural styles in the sedimentary cover (compression, transpression, and transtension) that formed simultaneously during the Late Cretaceous compression but with different directions.
The Application of Precision Ultrasonic Technologies to Diagnose and Identify Crossflow between Formations, Flow behind Pipe and Casing Leaks
Authors: Zakaria Mahmoud , Al-Shehri Ayedh , Tammar Hassan 
Published: July 2010

Abstract
Investigating the integrity of a casing, with the tubing in place, has always presented a challenge to operators worldwide. Even more challenging, is taking on an investigation into cross flow between formations & identifying regions of flow behind pipe, all while the tubing is still in place.
Flow behind pipe has always been a well debated subject amongst industry professionals; most advancement in this matter has been subjective, based on well educated speculation and largely dependent on temperature profiles and changes in the geothermal gradient. Saudi Aramco have recently utilized a new ultrasonic based, diagnostic technology, in order to map regimes of flow behind pipe, identify cross flow between downhole formations, locate casing leaks with a pin-point accuracy, all while the tubing is in place, and while using conventional Electric Line logging.
This technology exploits the innate physical properties of ultrasound. The capacity of ultrasonic waves to propagate through numerous and varied media, including steel, liquids & compressed gas; allows a radial investigation of up to 3m. Unlike several technologies that utilize ultrasound, this diagnostic tool, is a passive listener, with no transmitters. It is designed to pick up the sonic energy fluctuations created by the turbulent flow of fluids over a specific spectrum within the ultrasound frequencies window. A window that is so uniquely suited for precision wellbore diagnostics.
This paper presents the basic physics behind the technology chosen by Saudi Aramco to address the aforementioned issues. It will highlight the possible applications of these tools and more specifically discuss the recent case studies successfully performed in Saudi Aramco.
A Comparative Study Between Empirical Correlations & Mechanistic Models of Vertical Multiphase Flow
Authors: Yahaya Anes Usman , Al Gahtani Abdallah 
Published: July 2010

Abstract
A number of empirical correlations and mechanistic models have been developed for predicting pressure drop and other fluid flow characteristics during multiphase flow in vertical wellbore. At any particular time, engineers are often faced with the difficulty of which particular empirical correlation or mechanistic model should be used to evaluate multiphase flow in vertical wellbore. This is because; a particular correlation or model may be developed under some certain assumptions or for a particular region which may not be applicable to other regions or under a new set of conditions.
This paper presents a study that was conducted to evaluate the predictive performance of both mechanistically based models and empirical correlations in calculating pressure drop and other flow characteristics in vertical multiphase flow. Using 414 real field data points covering pipe sizes of 2.375 in. to 7.0. in, oil flow rate of 280B/D to 23,200B/D, water cut up to 95%, gas-oil ratio up 927SCF/STB from the Middle East, the correlations and models are used to predict pressure drop in vertical multiphase phase flow for several wells. The predicted performance is then compared with actual measured well pressure drop data.
The empirical correlations evaluated are those conventional correlations of Hagerdon and Brown, Duns and Ros, Orkiszewski, and Beggs and Brill. While mechanistic models of Ansari et al, Aziz et al, Chokshi et al are also evaluated. The variations between the predicted and the measured are analyzed using statistical error analysis.
Based on the results from the analysis, mechanistic model of Ansari et al. out-perform all the conventional empirical correlations evaluated in this study for vertical multiphase flow for the Middle East region.
Moving the Immovable: Practical Offshore Appraisal Testing of Heavy and Sour Oil
Authors: Al-Ajaji Abdulaziz A. , Al-Nahdi Abdul Hakim , Gill Harmohan , Omidiya Abdur-Rasheed 
Published: July 2010

Abstract
Saudi Aramco has recently embarked on an exploration program targeted at evaluating potential heavy oil reserves, offshore Saudi Arabia's eastern coast. The oil being tested is classified as heavy oil with an API gravity as low as 10 degrees (field measurement). Appraisal well testing in an offshore setting of such low API oil is difficult, especially when environmental considerations are of outmost importance. The tests objectives were to obtain accurate reservoir parameters, collect representative reservoir samples, and dispose of all produced hydrocarbons (heavy oil) without adversely impacting (spill/ polluting) the offshore environment. Being offshore, with limited space availability on jack-up rigs, it was also crucial that the design of the test equipment and procedures take into account the potential presence of Hydrogen Sulfide (H2s).
This paper will present best practices, experience gained, and lessons learnt from appraisal well testing of heavy oil at offshore locations. Several offshore heavy oil well tests were successfully carried out, where all produced hydrocarbons were flared off without causing spills or polluting the sensitive marine environment.
Flow Simulation in Inflow Control Valves Using Lattice Boltzmann Modeling
Authors: Qahtani Abdullah M 
Published: July 2010

Abstract
Flow simulation in inflow control valves (ICVs) plays an important role in production optimization and control. The number of ICVs required for deployment as well as their configuration impact strongly on the production forecast and planning. Optimization of ICVs focuses mainly on minimal flow disruption and pressure loss to allow continuous flow through a designated section. In some applications computational fluid dynamics (CFD) was employed to simulate the flow inside the inflow devices. These computational efforts based on solving the Navier-Stokes equations, always are subject to the type of geometry simulated which requires tremendous meshing efforts and the adequate of flow models to capture the physics involved in a particular flow mode. Frequently, single phase flows are only modeled in ICVs to visualize the basics of the fluid paths, but still require computational artifices to simulate the flow. Since more than a decade, lattice Boltzmann (LB ) flow simulations have shown gradual strength as an alternative to CFD methods. Opposite to traditional methods such as finite differences, finite elements, finite volumes, the LB methods (LBMs) are mesh free and only require little formulation efforts to simulate a fluid flow. On the other hand, LBMs do not always present problems often met in traditional CFD method such as long computational times, poor convergence and numerical instabilities. LBMs are more efficient since they are based on rigorous description of transport phenomena via the Boltzmann equation. In the present work, a flow simulation of a generic ICV configuration is shown by the use of an LBM. Flow properties and velocity distributions are shown and discussed for different flow scenarios. Based on these results, further design optimization can be proposed to minimize undesired effects such as excessive shear and additional pressure drop.