This paper investigates novel approaches to sour-gas treatment for use in the Middle East that are outside the common oil and gas market and compares them with traditional techniques. In the complete paper, a new, fully coupled implicit tool was used to model an onshore Omani asset with multiple reservoirs, each featuring different fluids and multiple networks. Processing sour natural gas is a challenge. If mercaptans are present in the sour gas, the limited mercaptan-absorption capacity of the well-known alkanolamine solvents can be a problem. An Excel-based tool was developed that uses cubic-equation-of-state (EOS) and thermodynamic electrolyte-chemistry modeling to assess sour-production streams.
This paper describes a novel method of chemical dosage based on time-resolved fluorescence (TRF) that allows a simple, accurate, and efficient quantification of chemicals below parts-per-million ranges, even for double (scale/scale, scale/corrosion) quantification. A study done to find the root cause of coiled tubing string failures in Montney indicated microbial-induced corrosion, leading the CT service provider to create a biocide treatment program. Rigless coiled-tubing-unit (CTU) interventions can be effective in returning to production wells that have lost electrical-submersible-pump (ESP) efficiency because of organic, inorganic, or mixed scale deposits. Sour gas is being produced from a number of carbon-steel-completed wells in the US, Canada, France, and Saudi Arabia. This work introduces sodium gluconate as an efficient and environmentally friendly iron-chelating agent.
Jin, Yan (China University of Petroleum at Beijing) | Jin, Guodong (Baker Hughes, a GE Company) | Syed, Shujath Ali (Baker Hughes, a GE Company) | Jin, Miao (China University of Petroleum at Beijing) | Hussaini, Syed Rizwanullah (King Fahd University of Petroleum and Minerals)
Subsurface unconventional shale samples are always scarce. Outcrop analogs are often used as an alternative to enhance the understanding of the corresponding reservoir formation. One assumption is usually made that rock composition and properties between the outcrop and subsurface samples remain the same or similar, despite differences in their burial and diagenetic histories. This paper presents a comparative case study to investigate the similarities and differences in rock properties between outcrop and subsurface samples from the same formation.
Two subsurface and two outcrop samples from the Lower Silurian Longmaxi formation in Sichuan Basin of China were characterized to determine their mineralogical, geochemical, petrophysical, elastic and mechanical properties. Micro-CT images showed that one subsurface sample was drilled normal to the bedding, while other three samples were parallel to the bedding. Two subsurface samples differ in their mineralogy – the horizontal sample is clay-dominant, while the other one is predominantly comprise of quartz, dolomite and calcite minerals, very similar to two outcrop samples. All four samples are thermally immature and their Tmax is less than 435 °C. Subsurface samples have the highest TOC of 3.75% but relatively lower HI and OI. Other pyrolysis parameters are very similar between subsurface and outcrop samples. All samples have very low porosity of less than 2.5% and permeability of less than 9 nD, although subsurface samples have a relatively higher value.
The discrepancy in mineralogical composition, especially the clay content, results in different elastic and mechanical behavior of outcrop and subsurface samples. The subsurface sample is highly anisotropic in both compressional and shear wave anisotropy due to the large amount of clay minerals, while one outcrop sample exhibits the strong shear wave anisotropy only and the other one is almost isotropic. Subsurface samples have lower values of Young's modulus, peak stress, Mohr-Coulomb failure parameters and unconfined compressive strength than outcrop samples.
Nielsen, Julie (The Danish Hydrocarbon Research and Technology Centre, Technical University of Denmark) | Poulsen, Kristoffer G. (Department of Plant and Environmental Sciences, University of Copenhagen) | Christensen, Jan H. (Department of Plant and Environmental Sciences, University of Copenhagen) | Solling, Theis I. (Center for Integrative Petroleum Research, College of Petroleum Engineering & Geoscience, King Fahd University of Petroleum and Minerals)
Mature fields often times surprise with respect to the production from the various wells across reservoir sections. This is for example the case in a tight chalk field that we have used as a case study for newly developed technique that employs oil finger printing in the analysis of production data. A small subset of wells has been found to produce significantly better than the remainder and we set out to explore whether the root cause is that there is a connection to higher lying reservoir sections through natural or artificial fractures. This was done with advanced analytical chemistry (GC-MS) and a principal component analysis to map differences between key constituents of the oil from wells across the reservoir section. The comparative parameters are mainly derived from biomarker properties but we also developed a way to directly include production numbers. The approach provides means to correlate the molecular properties of the oil with the production and the general composition that determines density and adhesive (to the rock) properties. Thus, the results provide a new angle on the flow properties of the oil and on the charging history of the reservoir. It is clear from the analysis that the subset of wells does not produce better because of a connection to an upper reservoir section that contributes to the production with oil of a different composition because the molecular mix is indeed quite similar in each of the investigated wells. It is not possible to rule out that there is a connection to an upper-lying section with oil from the same source. One aspect that does differs across the field is the ratio of heavy versus light molecules within each group of molecules and the results show that the region that produce better has the lighter components. We take that to indicate that the lighter components come from oil that flows better and thus is produced more easily. The reservoir section with the lighter oil also lies higher on the structure and is therefore must likely to have been charged first so part of the favorable production seems to be a matter of "first in" "first out". A GC-MS approach such as the one proposed here is cost-effective, fast and highly promising for future predictions on where to perform infill campaigns because the results are indicative of charging history and flow properties of the oil.
Review our data policy for information about these graphics and how they may be used. Integrated Historical Data Workflow: Maximizing the Value of a Mature Asset Industry studies show that mature fields currently account for over 70% of the world’s oil and gas production. Increasing production rates and ultimate recovery in these fields in order to maintain profitable operations, without increasing costs, is a common challenge. This lecture addresses techniques to extract maximum value from historical production data using quick workflows based on common sense. Extensive in-depth reservoir studies are obviously very valuable, but not all situations require these, particularly in the case of brown fields where the cost of the study may outweigh the benefits of the resulting recommendations. This lecture presents workflows based on Continuous Improvement/LEAN methodology which are flexible enough to apply to any mature asset for short and long term planning. A well published, low ...
To improve magnetic disturbance rejection and robustness of wellbore survey measurements, an adaptive neuro network-based fuzzy inference system (ANFIS) filter for wellbore position calculation is presented. This technique significantly improves magnetic disturbance rejection and reduces sensor error influence for borehole survey measurements. The new approach for the ANFIS filter is based on two redundant sets of IMUs which are located in different positions in the BHA at a known, constant distance. The distance between these two sets of IMUs will physically fade the effect of the magnetic disturbances. Each IMU set outputs position estimation based on the splines method which is then input into an ANFIS filter. The inputs of the splines calculation are azimuth, inclination angles and measurement depth, and the outputs are moving distance in three directions (Northing, Easting and True Vertical Depth). However, the accuracy of the splines method highly depends on the accuracy of the inputs, which are difficult to obtain during the measurement while drilling process even under pure clean environments (without any magnetic disturbances). Furthermore, the distorted azimuth caused by magnetic interference affects the borehole position accuracy. In order to deal with those problems, the designed ANFIS filter has a two-level structure. First a local level position estimation (splines method or well trained local ANFIS based on the sensor accuracy) for two sensor sets is used. If the sensor measurement accuracy is low, this local ANFIS will correct the position estimation. Then the outputs of the local modules were input into ANFIS for second level filtering (global filter) to remove the error which caused by unknown magnetic disturbances. According to the judgement of the ANFIS, the IMU set with the smaller magnetic disturbance is given greater weight to reduce the interference effect on the borehole position estimation. This two-level filter is compared to the traditional splines method under different tests situations. First, we evaluate this method by comparing with GPS positioning, from this test we know that the ANFIS filter shows a good performance when the magnitude of magnetic disturbance is within the training magnitude range. Even when the magnitude of magnetic disturbance is above the training range, the ANFIS filter shows a higher robustness than the traditional splines method. Also, this method was applied to borehole data with two IMU containing accelerometers and one magnetometer measurements. In order to apply our method, we duplicated one more magnetometer measurement data under magnetic interference for assessment. The results proved its magnetic disturbance robustness in borehole position estimation. Finally, we demonstrate the full potential using a laboratory experimental setup.
Maxime, France Geosteering Technologies - 9-14 September Downhole Water Management - 16-21 September Wells - How Smart Can They Get? - 23-28 September Asia Pacific Nusa Dua, Indonesia The Application of Seismic Attribute Analysis and Geostatistics in Reservoir Prediction - 13-18 May Optimising Well Productivity with Modern Completion and Stimulation Practices - 20-25 May South America and Caribbean Margarita Island, Venezuela Underbalanced Operations vs Designer Fluids - 28 October-2 November Middle East Muscat, Oman Produced Water Management - The New Reality - 3-8 November 2002 North America Park City, Utah, USA Enhancing Recovery from Deepwater Reservoirs - 7-12 July The Offshore Facility of the Future - 7-12 July E-Well and Wellbore Robotics - 14-19 July Decision-Driven Asset Development and Management - 14-19 July Europe Ste. Saint Maxime, France Smart Drillling - 5-10 September Sand Control and Management - 12-17 September Tight Gas Development - 19-24 September Middle East Muscat, Oman Smart Wells: How Smart Can They Get? - 10-15 January Mature Reservoirs: The Appropiate Application of Technology - 17-22 January P a g e 13 17 Middle East Hammamet, Tunisia The Heavy Oil Challenge: Completion Design and Production Management - 17-22 May 2010 North America Park City, Utah, USA Meet me at the Wellhead - Enhancing the Value Chain in Offshore Installations - 20-25 June - Cancelled Getting to Zero-An incident Free Workplace: How do we get there? P a g e 14 17 Europe The Algarve, Portugal Unlocking the Potential of Nanotech for Exploration and Production - 25-30 September Shale Gas: Beyond Current Technologies and Going Global - 2-7 October CO2 Geological Storage: Will we be ready in time? Can supply expand to keep up with demand exceeding projections? P a g e 15 17 Europe Adaptive Well Construction - 13-18 October Managed Pressure Drilling - Niche Technology or the Future of Drilling?
Chen, Zhiming (State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, and University of Texas at Austin) | Liao, Xinwei (China University of Petroleum, Beijing) | Yu, Wei (Texas A&M University and University of Texas at Austin) | Sepehrnoori, Kamy (University of Texas at Austin)
Fracture networks are extremely important for the management of groundwater, carbon sequestration, and petroleum resources in fractured reservoirs. Numerous efforts have been made to investigate transient behaviors with fracture networks. Unfortunately, because of the complexity and the arbitrary nature of fracture networks, it is still a challenge to study transient behaviors in a computationally efficient manner. In this work, we present a mesh-free approach to investigate transient behaviors in fractured media with complex fracture networks. Contributions of properties and geometries of fracture networks to the transient behaviors were systematically analyzed. The major findings are noted: There are approximately eight transient behaviors in fractured porous media with complex fracture networks. Each behavior has its own special features, which can be used to estimate the fluid front and quantify fracture properties. Geometries of fracture networks have important impacts on the occurrence and the duration of some transient behaviors, which provide a tool to identify the fracture geometries. The fluid production in the fractured porous media is improved with high-conductivity (denser, larger) and high-complexity fracture networks.
Zhao, Kai (Xi’an Shiyou University and Shanxi Key Laboratory of Advanced Stimulation Technology for Oil & Gas Reservoirs) | Li, Xiaorong (University of Texas at Austin) | Yan, Chuanliang (China University of Petroleum, East China) | Feng, Yongcun (The University of Texas at Austin) | Dou, Liangbin (Xi’an Shiyou University) | Li, Jing (China University of Petroleum, East China)
Fault reactivation caused by reservoir depletion has been an important issue faced by the oil and gas industry. Traditional views suggest that with reservoir depletion, only normal faults can be activated and fault stability either monotonically decreases or increases, which are not consistent with field observations. In this paper, a fault-sliding-potential (FSP) model was developed to analyze fault stability during reservoir depletion for different types of faults. The evolution trend of fault stability with reservoir depletion and the corresponding judging criteria were obtained by calculating the derivatives of FSP. The influences of reservoir depletion on nonsealing and sealing faults were investigated. Case studies were performed to analyze FSP for different types of nonsealing and sealing faults with different fault properties and attitudes. The results show that reverse and strike faults might also be reactivated with reservoir depletion. The fault stability might not monotonically decrease or increase; instead, four evolution patterns of fault stability might occur, with reservoir depletion dependent on the parameters of the faults. Reservoir depletion usually leads to a higher sliding risk for sealing faults than for nonsealing faults. The results also indicate that fault stability is a strong function of fault attitudes, including the dip and strike of the fault.
Langé, Stefano (TOTAL S.A. 2 Place Jean Millier) | Zhao, Jing (TOTAL S.A. 2 Place Jean Millier) | Cadours, Renaud (TOTAL S.A. 2 Place Jean Millier) | Weiss, Claire (TOTAL S.A. 2 Place Jean Millier) | Bernadet, Mikael (SOBEGI Induslacq) | Caetano, Michel (SOBEGI Induslacq) | Layellon, Lise (SOBEGI Induslacq)
This paper presents how the optimization of the solvent composition provides significant OPEX reduction and simplifies process management.
Removing mercaptans from natural gas is becoming a tough work for operating companies due to the tightening of commercial specifications for sulfur-containing molecules in the final products. Beside this, about 40% of the known gas reserves are sour; some of them contain H2S and mercaptans. To commercialize these gas fields in a profitable way, smart process solutions focused on energy efficiency are needed. Classical gas sweetening units are based on chemical absorption by means of aqueous alkanolamines to remove CO2 and H2S from natural gas. These solvents have limited mercaptans removal capacity, requiring supplementary removal processes. This has a negative impact on the overall gas processing costs.
To face this challenge, TOTAL has developed a new series of hybrid solvents able to remove, in a one- step operation, CO2, H2S and mercaptans. Process performances can be improved without plant modification. The first solvent formulation was based on DiEthanolAmine (DEA) and was implemented in the sweetening units of the Lacq plant (France), demonstrating the benefits of the new hybrid solvents at industrial scale.
DEA solvent is a widely used and easy-to operate/monitor solvent. However, DEA has the drawback to be sensitive to chemical and thermal degradation. Moreover, DEA regeneration is quite energy demanding.
To overcome these problems, the amine components have been changed. The choice of new components is driven by following characteristics: good solvent stability, low regeneration energy demand, high CO2 and H2S removal efficiency.
A mixture of MethylDiEthanolamine and Piperazine (MDEA+PZ) has been adopted as the solution to replace the DEA based solvent. The choice has been made thanks to the good chemical stability of MDEA and the high performance of PZ as an activator to boost the rate of the absorption process.
This paper presents the operational feedback with this new formulation. The first benefit of the hybrid solvent formulated with MDEA+PZ is that it was implemented in the existing unit without plant modification. Other advantage is the improved chemical and thermal stability. This solvent swap allows to decrease the reboiler duty of the solvent regeneration, to reduce the chemicals consumption, while keeping the final product quality unchanged.
The benefits of the solvent swap will be supported by operating data collected before and after the solvent swap.