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Results
A New Paradigm for Automatic Well Path Generation Using Multidisciplinary Constraints
Cayeux, E. (NORCE Norwegian Research Center, Stavanger, Norway) | Pelfrene, G. (NORCE Norwegian Research Center, Stavanger, Norway) | Mihai, R. (NORCE Norwegian Research Center, Stavanger, Norway) | Dvergsnes, E. (NORCE Norwegian Research Center, Stavanger, Norway) | Tjøstheim, B. P. (Equinor, Stavanger, Norway) | Baume, A. (TotalEnergies, Pau, France) | Khosravanian, R. (Halliburton, Stavanger, Norway) | Kristiansen, T. G. (Aker BP, Stavanger, Norway)
Abstract The well planning process involves many disciplines. Due to the multidisciplinary nature of the process, many iterations are necessary to generate a well path. This is a time-consuming process that finally leads to chosen planned trajectories that may be sub-optimal. It is proposed to radically revise the well path generation process to reach the vision of planning a well in one day with high quality. Departing from the traditional incremental approach to well path generation, the proposed method relies on the collection of experienced-based constraints from each discipline to generate possible alternatives to the well path. A fundamental difference with the classical well path generation process, which works with one or a handful of planned trajectories, is that an ensemble of possible well paths is generated through the proposed method. If the constraints are loose, many planned trajectories might be generated but if the constraints are tight, there may be very few or possibly no solutions. As a result of this new work process, the multidisciplinary team can focus on the relevance of the constraints rather than on the details of the planned trajectory. Capturing these constraints is the fundamental result of the well planning process; the ensemble of possible well paths being only a byproduct of it. The novel method comes with a set of concepts that provide subject matter experts with greater leeway for defining the well path generation problem in a generic way. These concepts have been designed to seamlessly allow for any subsequent updates of the well plan, whether for the target or group of targets and their associated wellbores, the wellbore architecture and its relation to geo-pressure margins, or the surveying program with regards to wellbore position uncertainty. Whenever possible, characteristics attached to these concepts are described implicitly to cope with mutual interactions between constraints. An extensible classification of the constraints is provided and illustrated with examples commonly used to define drilling programs. As a result of the propagation of user-chosen constraints, complex problems such as finding well paths that respect anti-collision criteria, avoid faults or cross them with a high incidence angle if unavoidable, and satisfy inclination limits to cross certain formation layers are solved completely automatically. Innovation does not come for free: the new paradigm presented in this paper induces a significant transformation of the well planning process. However, the versatility of the approach should largely compensate for the expected change in end-users’ habits both by a faster delivery time of every well plan (or even large-scale field development) and by allowing a seamless update of the latter when drilling operations demand it.
- Europe (0.68)
- South America (0.67)
- North America > United States > Texas (0.28)
- Geology > Geological Subdiscipline > Geomechanics (0.68)
- Geology > Structural Geology > Fault (0.46)
- Geology > Structural Geology > Tectonics (0.46)
- South America > Colombia > Casanare Department > Llanos Basin > Guachiria Block > Cusiana Field (0.99)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Planning & Scheduling (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Constraint-Based Reasoning (0.94)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Search (0.67)
Abstract Barik Sandstone is a well know condensate reservoir developed in several fields across Central Oman between Ghaba Salt Basin and Fahud Salt Basin. Its particularity lays in the vertical and lateral heterogeneity resulting from the fluvial-deltaic depositional environment and an associated quite unusually high stress differential across the different mudstone and sandstone members. Barik is classified as Unconventional Tight Gas due to the low average permeability and requires hydraulic fracturing (HF) to economically exploit the natural resources. Understanding the reservoir parameters was a key success for successful stimulation of the Barik Sandstone in Khazzan and Ghazeer Fields in Oman. A massive surveillance campaign was carried out to understand the reservoir properties including detailed seismic and long-term flowing and build up data. building a calibrated Mechanical Earth Model MEM allowed the team to design the best fit frac design that made the successful results on frac placement and well performance. With the extension of the reservoir height, more data were used to update the Mechanical Earth Model that helped to refine the frac design. this paper describes the workflow of how additional data helped modifying frac design using DFIT injections & different frac design approaches across different barriers. The Mechanical Earth Model created at the early stage of the field development was generated using a detailed Microfracs stress test and reservoir properties using static and dynamic data. layers stresses confirmed using several frac injection to test the break down pressure of that layer which then helped into defining the best frac design for the reservoir. The successful stimulation treatments confirm the value of such detailed surveillance and details workflow that was continuously updated using frac injections. This has a major impact on frac performance and field development plan that reflect the outstanding performance of these wells.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.77)
- Geology > Sedimentary Geology > Depositional Environment > Transitional Environment > Deltaic Environment (0.54)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.49)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- Asia > Middle East > Oman > Ghaba Salt Basin (0.99)
- Asia > Middle East > Oman > Fahud Salt Basin (0.99)
- (21 more...)
Pre-Drilling Prediction of 3D Geomechanical Parameters Based on Seismic Data: A Case Study of Tarim Oilfield
Zhou, Bo (PetroChina Tarim Oilfield Company) | Zhang, Xin (China University of Petroleum Beijing) | Zhao, Li (PetroChina Tarim Oilfield Company) | Zhou, Bao (PetroChina Tarim Oilfield Company) | Chen, Long (PetroChina Tarim Oilfield Company) | Lu, Yunhu (China University of Petroleum Beijing)
ABSTRACT A pre-drill prediction method of 3D geomechanical parameters based on seismic data is proposed. Firstly, the wave impedance parameters are predicted in the target area by the logging-constrained method, which mainly uses post-stack seismic data and logged data from drilled wells. The density and velocity data are obtained by separating the wave impedance data. Then, the density and velocity data are used as input to calculate 3D geomechanical parameters in the region, including elasticity parameters, strength parameters, and stress parameters. In particular, experimental data are used to correct the accuracy of the model. The results accurately reflect the geological complexity and non-homogeneity of the region by evaluating the elastic properties, mechanical properties, and stress magnitude of each point. This method can greatly improve the longitudinal resolution of the inversion results by fully exploiting a priori information from the logs and involving them in the seismic inversion process. Pre-drill parameters prediction of a complex field in the Tyuritag of the Tarim Basin is carried out. INTRODUCTION A growing number of oil and gas field development projects are facing the challenge of safe, rapid, and efficient development, such as offshore projects like Hibernia and the Gulf of Mexico in Canada, and onshore projects in tectonically active areas like the Cusiana field in Colombia and the Tarim Basin in China. However, as drilling depths continue to deepen, the geological environment encountered in oil and gas development is becoming increasingly complex. The difficulty of engineering problems related to geomechanics is also increasing. On the one hand, there are more and more complex accidents in various wells, such as well wall instability, well leakage, and sand production. Underground accidents seriously increase the time and cost of construction operations. It is estimated that at least 10% of the average well budget is used for unplanned operations due to wellbore instability (Sheng, 2006; Wei, 2012). On the other hand, the inaccuracy of geomechanical modeling makes geomechanics-related engineering measures unable to achieve the expected goals. In shale oil and gas development, about 30-50% of fracturing clusters do not contribute to product improvement. The root cause is poorly designed hydraulic fracturing strategies due to the lack of accurate geomechanical data (Zhang, 2018; Parshall, 2015).
- North America > United States (1.00)
- Asia > China > Xinjiang Uyghur Autonomous Region (0.45)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- Asia > China > Xinjiang Uyghur Autonomous Region > Tarim Basin (0.99)
- North America > United States > Texas > East Texas Salt Basin > East Texas Field > Woodbine Formation (0.98)
- Well Drilling > Wellbore Design > Wellbore integrity (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Reservoir geomechanics (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
Coupled Numerical Simulation of the Dynamics of Deepwater Steel Lazy-Wave Riser Under the Full-Stages of Severe Slugging
Gaji, Ameena Abba (College of Safety and Ocean Engineering, China University of Petroleum / Craft and Hawkins, Louisiana State University) | Onuoha, Mac Darlington Uche (College of Safety and Ocean Engineering, China University of Petroleum) | Duan, Menglan (College of Safety and Ocean Engineering, China University of Petroleum) | Lee, Min Jun (College of Safety and Ocean Engineering, China University of Petroleum)
ABSTRACT Severe slugging is a flow assurance problem that threatens the integrity of offshore production systems due to its cyclic behaviour and a source for fatigue damage in the material structure. Due to the complicated nature of the physics of severe slugging and its interactions with the pipe structure, no study has fully understood the dynamic behaviour of steel lazy-wave risers induced by the 4 stages of severe slugging and of which this research draws its originality from. In this paper, a 2-way full coupled FSI numerical model is simulated with ANSYS-FLUENT, ABAQUS and MpCCI, respectively, for the numerical investigation of the interaction between the complete flow stages of severe slugging and the dynamic response & stress impact on a steel lazy-wave riser. A comingled two-phase flow and 2D pipe with 0.05 m ID, 0.075 m OD and −5° pipe inclination was modelled. MpCCI serves as the coupling interface server for real-time pressure and structural deformation data exchanges. Results show that the dynamic response is critical at the downcomer during the gas blowout and liquid fallback stages. Findings from this study will help to improve on the fatigue design of deepwater risers for structural reliability, safety and enhanced fatigue life. INTRODUCTION Severe slugging also referred to as terrain-induced slugging can be defined as a two-phase flow phenomenon which is peculiar in subsea production systems and occur mostly in aged oil fields which are susceptible to heavier oil deposits, low flow rates, pressure fluctuations, and the unevenness in the seabed topography. It is a critical condition that results in fatigue loading and material damage in the pipeline riser system, and as a result, poses a threat on the structural integrity, reliability and safety of offshore production facilities. Yocum (1973) was the first to report the phenomenon of severe slug flows which has a prone occurrence in petroleum offshore facilities, where usually there are downward sections (pipelines) and upward sections (risers). In the history of experimental studies on severe slugging, Schmidt, James, and Beggs, (1980) were the first to describe the occurrence of severe slug flows in pipeline riser systems. Their research majorly classified severe slugging into four stages: slug formation, slug production, gas blowout and liquid fallback. Studies such as (Boe, 1981; Balino, Burr, and Lovate, 2007; Fabre, Peresson, Corteville, Odello, and Bourgeois, 1990; Schmidt, James, and Beggs, 1980; Taitel and Barnea, 1990) have highlighted several severe slugging problems such as high back pressure at the wellhead, loss in production due to separator process failure caused by stream surges, instability in control systems of the separator, reservoir flow oscillations, platform trips and equipment failure due to fatigue loads.
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Risers (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Pipeline transient behavior (1.00)
Chemical in Gas Dispersions: The Evolution of a Novel Concept for IOR/EOR in Tight Formations
Ocampo, Alonso (GaStim Technologies) | Restrepo, Alejandro (GaStim Technologies) | Díez, Kelly (GaStim Technologies) | Rylance, Martin (SPE) | Patiño, Jonny (GaStim Technologies) | Rayo, Juan (GaStim Technologies) | Ayala, Diego (GaStim Technologies)
Abstract The development and application of chemical-in-gas stable dispersions is described for use as a novel approach to IOR/EOR in tight formations. The development of this unique process as a stimulation and recovery method is described through workflow processes and field examples. The injection of chemical-in-gas stable dispersions was first proposed, outlined, and described in two key publications by Restrepo et al. in 2012 [Restrepo et al, 2012]. Since then, an extensive suite of successful enhanced-recovery well trials and operations have been executed, across the complex compositional reservoirs of the Andes foothills. Detailed information related to droplet transport, retention, and adsorption phenomena, occurring during placement, soaking and back production; has been obtained. These behaviors have then been examined using mathematical models and numerical approximations; as well as being calibrated to core results. Widespread and successful IOR/EOR field applications have included condensate bank removal, gas injection conformance, asphaltenes dissolution/inhibition and induced water blockage removal. Typical oil and gas production increases, achieved after the injection of the chemical-in-gas dispersions for IOR, have ranged between 15% and 35% depending upon the pre-existing well/reservoir conditions, available data for planning and the detail of the treatment characteristics itself. Also, for IOR, long term production sustainability of between 3 to 15 months has been achieved depending upon the chemical adsorption and desorption effectiveness and damage restoration rates. This period of sustainability is 2 to 3 times that achieved by more conventional methods. Most recent enhancements to the technique include the chemical screening and core-flood testing of new and advanced IOR/EOR chemical solutions. These include the application of dispersible RPMs as well as encapsulated acids for clay dissolution; this has been complemented by the development of bespoke simulation tools to simulate the fundamental physics of the process. This work presents a detailed overview of the observations, learnings and remaining challenges related to the injection of chemical-in-gas stable dispersions. Reporting on several field applications that are then also history matched with the latest modelling approach. Finally, a discussion pertaining to the most recent chemical-in-gas dispersion systems and deployment prototypes will be presented as the foundation for a suite of new and novel IOR/EOR techniques available to the industry.
- North America > United States > Texas (0.93)
- North America > Canada (0.68)
- South America > Colombia (0.68)
- Europe > United Kingdom (0.68)
- Geology > Rock Type > Sedimentary Rock (0.46)
- Geology > Geological Subdiscipline (0.46)
- Geology > Mineral > Silicate (0.34)
- Geology > Structural Geology > Tectonics > Compressional Tectonics > Fold and Thrust Belt (0.34)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- South America > Colombia > Casanare Department > Llanos Basin > Cupiagua Field (0.99)
- North America > United States > Texas > West Gulf Coast Tertiary Basin > Eagle Ford Shale Formation (0.99)
- (5 more...)
Foam Formulation Development and Pilot Application in Low-Permeability Reservoirs
Zou, Xinyuan (University of Science and Technology Beijing) | Luo, Wenli (State Key Laboratory of Enhanced Oil Recovery, Petrochina Research Institute of Petroleum Exploration & Development) | Wang, Zhengbo (State Key Laboratory of Enhanced Oil Recovery, Petrochina Research Institute of Petroleum Exploration & Development) | Jiang, Zhibin (State Key Laboratory of Enhanced Oil Recovery, Petrochina Research Institute of Petroleum Exploration & Development) | Han, Xu (Research Institute of Petroleum Exploration & Development, PetroChina Xinjiang Oilfield Company) | Chang, Zhidong (State Key Laboratory of Enhanced Oil Recovery, Petrochina Research Institute of Petroleum Exploration & Development)
Abstract Foam flooding has been widely studied and implemented in recent years to alleviate reservoir heterogeneity and increase oil recovery. Previously, foam flooding was employed for conformance control and improving sweep efficiency, and little attention was paid to displacement efficiency. Thus, foam flooding usually had a poor ability to trip off oil film. Moreover, the effectiveness of many of the foam pilots lasted only a few months, and, in some cases, only a few weeks, which limited the long-term development of foam in field applications as the time to maximize effectiveness was too short. In this paper, a foam pilot selection, formulation design, and N2 foam pilot implementation are presented towards providing an effective method for transforming the development mode after water flooding in low-permeability reservoirs. Two well groups (two injection wells and 17 production wells) were screened as candidates for the N2 foam pilot. Laboratory investigations included bulk foam screening, imbibition recovery, and natural core flooding tests. One formulation of eight tested (No. 6) showed excellent foam properties as well as a strong ability to strip oil from sand, and natural core scale work under reservoir conditions resulted in a total recovery of 66.92%, with an incremental recovery of 25.25% by N2 foam after water flooding. The pilot was deployed using a new injection strategy of a surfactant alternating gas method in which surfactant was injected into water for 1 d at a normal injection rate followed by N2 injection for 1 d at a large injection rate. A positive response was observed after injection for approximately 1.5 months, daily oil production climbed sharply, and water cut also decreased after processing of 1% of pore volume with foam solution. Moreover, production was sustained for 18 months after foam injection, which resulted in approximately 4375 t of incremental oil. The foam pilot was successful in addressing the challenges associated with dominant channel and low displacement efficiency of water flooding in low permeability sand reservoirs.
- Asia (1.00)
- North America > United States > Texas (0.69)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- North America > United States > Wyoming > Powder River Basin > Salt Creek Field (0.99)
- North America > United States > Texas > Fort Worth Basin > Woodbine Field (0.99)
- (2 more...)
New Engineering Approach Using State of the Art RSS to Overcome Complex Colombian Foothills and Improving Drilling
Hernandez, Juan Manuel (SLB) | Gomez, Jose Luis (ECOPETROL SA) | Lopez, Alexander (ECOPETROL SA) | Garzon, Fredy (SLB) | Celis, Manuel (ECOPETROL SA) | Montes, Daniel (ECOPETROL SA) | Gamba, Ivan (SLB)
Abstract Drilling in Colombian foothills have been a big challenge since BP drilled on this area in 1987, currently operating by Ecopetrol S.A foothill implementing innovative well design and new technologies. This basin has been characterized by its complex geological conditions, structure full of faults and high stresses that make drilling operation a big challenge. New well construction engineering based on thorough offset wells and NPT events analysis in addition to the implementation of lessons learned from previous wells in the area, combined with state-of-the-art rotary steerable system have changed the way of drilling in Colombian foothills field overcoming all the challenges faced in the past. To achieve this success, the following approach was followed: Concatenate well profile to balance dogleg severity to minimize tortuosity to allow running the casing smoothly Innovative well design to achieve exploration objectives in Cupiagua XD45, a well drilled by Ecopetrol S.A. in 2022. BHA optimization including state-of-the-art rotary steerable system to enhance the drilling performance. Transient finite element simulation for 12 ¼" × 14 ¾" section to determine optimum rotary steerable BHA and underreamer cutting structure configuration to achieve smooth drilling condition and borehole quality. This integrated approach allowed to: Optimize well trajectory design process achieving lower and concatenated dogleg severities driven by formation dips bedding to avoid wellbore instability problems Optimum BHA design and stabilization to minimize stuck probability and assure an optimal BHA dynamic while drilling the well Minimize borehole tortuosity using last generation of RSS system to achieve smooth borehole quality enhancing tripping, drilling, and running the surface casing and intermediate liner, improve drilling, tripping and casing run performance. Simulation and technical analysis to choose the proper bit profile and design correct underreamer’s cutters to run on 12 ¼" × 14 ¾" section to deliver good wellbore quality and allow smooth 11 ¾" × 11 7/8" liner. This new well construction engineering approach represent an effective solution to overcome Andean foothill challenges achieving optimum borehole quality and improving drilling performance in complex drilling environment by incorporating state-of-the-art RSS
- North America > United States > North Dakota > Burke County (0.24)
- South America > Colombia > Meta Department (0.15)
- Geology > Geological Subdiscipline > Stratigraphy (0.49)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.48)
- Geology > Structural Geology > Tectonics (0.47)
- South America > Colombia > Mirador Formation (0.99)
- South America > Colombia > Meta Department > Llanos Basin > Cano Sur Block > Carbonera Formation (0.99)
- South America > Colombia > Llanos Basin > C7 Formation (0.99)
- (3 more...)
- Well Drilling > Wellbore Design > Wellbore integrity (1.00)
- Well Drilling > Well Planning > Trajectory design (1.00)
- Well Drilling > Drillstring Design (1.00)
- (4 more...)
Integrity Investigation of Macroscopic and Microscopic Properties of Non-Aqueous Foams for Enhanced Oil Recovery
Li, Yibo (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University) | He, Tianshuang (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University) | Zhao, Jinzhou (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University) | Lin, Xiang (No.3 Oil Production Plant of Changqing Oilfield Company) | Sun, Lin (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University) | Wei, Bing (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University) | Pu, Wanfen (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University)
Abstract Foam flooding is a crucial enhanced oil recovery technique for profile control during the oil displacement process. The stability of the foam is the key factor for the success of foam flooding, but typical aqueous foams generally lose their stability in the presence of hydrocarbons because of their low oil tolerance. Non-aqueous foams possess outstanding stability in the presence of hydrocarbons as a result of their unique properties. However, few studies have been conducted on the stabilization mechanisms of non-aqueous foams in the presence of hydrocarbons. In this study, comparative experiments were performed to investigate differences in the stabilization mechanism between aqueous and non-aqueous foams. The results showed that a non-aqueous foam had excellent oil tolerance in a bulk foaming test. Then, the stabilization mechanisms of foams were investigated in terms of surface dilatational viscoelasticity and liquid film thinning. For a non-aqueous foam system, the maximum viscoelastic modulus of 55 mN/m occurred at a surfactant concentration of 5.0 wt%, which indicated that the foam was more stable. In a foam film thinning experiment, the thinning time of an aqueous foam system was shortened but the liquid film thickness was increased by crude oil, whereas crude oil increased the thinning time of a non-aqueous foam system but decreased its liquid film thickness. In a non-aqueous foam system, the film could remain stable for hours before rupturing, which indicated that its stability in the presence of an oil phase was excellent. These results are meaningful for the understanding of the stabilization mechanisms of oil-based foams and the employment of non-aqueous foams for enhanced oil recovery.
- Asia (0.94)
- North America > United States > Texas (0.28)
- South America > Colombia > Mirador Formation (0.99)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- North America > United States > Texas > Fort Worth Basin > Woodbine Field (0.99)
- (5 more...)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Gas-injection methods (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Chemical flooding methods (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (0.68)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Miscible methods (0.68)
Abstract Reservoir development from exploration to abandonment benefits from integrated geomechanical modeling to set guidelines and long-term operational strategies. Due to increasing operational challenges, geomechanics has become an essential part of the oil and gas industry’s daily route practice. These challenges arise when dealing with deep and tight, unconventional subsalt reservoirs, especially when drilling deviated or horizontal boreholes in a depleted formation in the minimum stress direction when intended to place multistage hydraulic fractures. This study provides innovative geomechanical solutions to address exploration challenges. This integrated approach will incorporate all available data to construct 3D geomechanical static models to assess and characterize the reservoir properties. These properties include reservoir quality index, sweet spot, reservoir compartmentalization, pore pressure prediction, in-situ stress regime, and presence of faults and fractures. The study will also investigate the relationship between in-situ stress, fractures, faults distributions, and fluid flow and correlate fracture properties variations to the lithology changes. The results from this study will be used as guidelines strategies for hydrocarbon exploration. The research will address the impact of the in-situ stress variations on petroleum systems, fault seal integrity evaluation, reservoir mapping, and heterogeneity. The study also provides an understanding of vertical and lateral variations of the in-situ stresses and their impact on well placement and well spacing. The types of geomechanical modeling implemented here can be used to accurately drill a safe and cost-effective wellbore that meets completion and stimulation requirements and maximize hydrocarbon production. Implementing this innovative geomechanical workflow addresses exploration challenges and plays an essential role during reservoir development to characterize the reservoirs and optimize operations. The studies showed that implementing this workflow improves reservoir developments by saving millions of dollars and minimizing the non-productive time during the planning and exploration phase.
- Asia > Middle East > Saudi Arabia (0.46)
- North America > United States > Texas > Harris County > Houston (0.28)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.32)
- Geophysics > Borehole Geophysics (0.94)
- Geophysics > Seismic Surveying > Seismic Modeling > Velocity Modeling (0.48)
- Geophysics > Seismic Surveying > Seismic Processing (0.48)
Abstract Numerous wellbore instability problems have been reported when drilling through laminated shale formations because of anisotropic (weak) strength along bedding layers. The anisotropic strength is defined through the analysis of stress distributions around wellbore and angle of intersection (AOI) between well trajectory and weak bedding plane. This paper presents a method to calibrate a wellbore stability model, design mud weight and control breakout width based on analysis of AOI and anisotropic strength. The proposed method includes four (4) steps as follows:AOI is calculated by using bedding plane data (dip angle and dip azimuth) and well trajectory information (well inclination and azimuth). Based on single plane of weakness theory, the stress distributions around deviated wellbores in laminated shales are analyzed to show that failure can occur either along or across bedding planes depending on AOI. The profile of collapse pressure for both isotropic and anisotropic strength model are calculated along with the AOI. Drilling data (mud weight, cuttings/cavings pictures etc.) combined with azimuthal density image are used to choose and calibrate the wellbore stability model. Lab strength test results with different angle to bedding plane are used to calibrate rock strength model and field data are collected and analyzed to define acceptable breakout width. Field data demonstrates that AOI can have a significant effect on wellbore stability. It is observed that severe borehole problems occurred in hole sections with low AOI (<30°) especially when a low mud weight is used to allow a wider breakout. Minor wellbore instability still occurred in some hole sections with low AOI even when the zero breakout criteria was used for mud weight selection. The instability observed can be attributed to swab – decreased ESDs being exerted on the formation while pulling the bottom-hole-assembly out of the hole and time-dependent effect. The ‘zero breakout width’ criterion is recommended for AOI less than 30°, the ‘(90°-Inclination) breakout width’ criterion for AOI between 30° and 60°, and the ‘(90°-2/3*Inclination) breakout width’ criteria for AOI greater than 60°. If the mud weight window permits, then it would be beneficial to increase the mud weight by an extra 0.2 ppg to cover swab effects in shale formations that have an extremely low AOI (<15°). If not, mechanical means to prevent hydrostatic pressure drops such as slower pipe reciprocation or managed pressure drilling (MPD) need consideration.
- Europe (1.00)
- North America > United States > Texas > Harris County > Houston (0.28)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Geology > Geological Subdiscipline > Stratigraphy (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- South America > Colombia > Casanare Department > Llanos Basin > Cusiana Field > Mirador Formation (0.99)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- (11 more...)
- Well Drilling > Wellbore Design > Wellbore integrity (1.00)
- Well Drilling > Drilling Operations (1.00)
- Well Drilling > Drilling Fluids and Materials > Drilling fluid selection and formulation (chemistry, properties) (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)