Baker Hughes (United States)

Abstract Faults are weak areas in rocks; however, faults have a very important impact on the construction and operation of underground gas storage. When gas is injected or produced into the gas storage, the increase or decrease in pore pressure in the surrounding rock mass may cause fault slip. A three-dimensional geomechanics model is established to study the evaluation methods and indicators of fault slip activation under alternating working conditions of gas storage. To accurately evaluate the stability of faults under alternating stresses and quantify their bearing capacity, this study established a three-dimensional dynamic rock mechanics model based on a fine three-dimensional geological model, combining one-dimensional rock mechanics modeling data and reservoir simulation results. This model uses a reservoir simulator and a rock mechanics simulator to calculate in synergy to reflect how the periodic pressure fluctuations inside the formation affect the local underground stress field and cause elastic and plastic deformation of the formation rock. Then, based on the relevant rock mechanics principles, the stability of the fault within the designed operating range can be quantitatively evaluated to optimize the operating pressure range of the gas storage in the best way. Set the fault to be open or closed for numerical simulation, observe the changes in the pressure monitoring curve of the monitoring well near the fault, and compare the observed curve with the pressure curve of the injection and production operation cycle to determine the closure of the fault. The calculation results show that one of the three faults is open. Drilling accidents are identified and analyzed to provide calibration data for formation stress and rock mechanics models, and a reliable three-dimensional geomechanics model is established. The grids through which the fault passes are marked as fault units, and their mechanical properties are obtained by distributing the equivalent rock mechanics parameters according to the different weights of the fault and the intact rock, and quantitatively describe the shear force, normal stress, pore pressure and friction coefficient acting on the fault plane. Based on the analysis of the maximum pressure rise in the geomechanics state and weak faults, the minimum limit formation pressure of the three faults is 42.5 MPa. Based on the analysis results of the gas storage fault, the ultimate bearing pressure of the gas storage is about 42MPa. Safety is always the top priority for gas storage. In addition to deploying monitoring wells, numerical simulation and rock mechanics research were also conducted to determine the evaluation method and calculate the safety index parameters for the safe operation of gas storage during the alternation of injection and production conditions, setting a benchmark and example for the operation of similar gas storages in this oilfield.

Abstract Sand-related degradation remains the primary constraint on Electric Submersible Pump (ESP) reliability in the BS field of the R Block, with Dismantle Inspection and Failure Analysis (DIFA) repeatedly documenting impeller/diffuser erosion, thrust-washer wear, and solids packing in stage clearances. These observations indicated that the dominant mechanism was not only abrasive cutting, but also adhesive fines bridging and torque instability, which conventional hardware-based solutions alone could not fully mitigate. In response, a field-engineered ESP–chemistry integration program was deployed in nine wells, combining multi-expertise in ESP design, materials, production operations, and oilfield chemistry. A non-ionic sand dispersant formulation selected through compatibility review, operating-envelope screening, and dose-effect evaluation was delivered via continuous capillary injection at the ESP intake. Performance was evaluated under normal operating conditions using run life, overload activity, motor-current behavior, and surface solids/BSW signatures, with overloads, deferred days, and lost-production opportunity (LPO) normalized to an annual basis to enable consistent comparison across wells. The operating strategy applied an initial conditioning phase at ∼200–300 ppm followed by controlled step-down toward ∼100–200 ppm as current stabilized and separation remained intact. The program demonstrated a material improvement in ESP reliability and operating behavior. Run life increased in seven of ten wells, shifting the median from 134 to 239 days (+78%) and increasing the mean by 131 days. Annualized overloads declined from 82 to 45 events (−45%), LPO decreased from ∼7,079 to ∼2,836 bbl/yr (−60%), and annualized deferred days dropped from ∼1,146 to ∼73 days/yr (−93%). Responding wells exhibited a consistent sequence: an initial surface fines purge, convergence of amperage from saw-tooth to tight-band profiles and sustained lower trip frequency at the stabilized dose. The economic implication is favorable at field scale. Across the responding wells, four deferred workovers collectively avoided approximately ∼$0.10 MM in rig exposure, while 760 – 1050 incremental well-days of uptime correspond to ∼30 – 42 kbbl of potential recovery at 40 BOPD. These outcomes are tied to the engineered pairing of ESP operating envelope, materials compatibility, and field-tuned dispersant delivery, and should not be generalized to unsupported chemical substitution. Overall, the work shows that when fines-driven adhesive behavior governs failure, capillary-delivered, interface-wetting dispersion can stabilize stage clearances, damp torque excursions, and extend ESP run life as a complement not a replacement to mechanical design and sand-handling practices.

Abstract This work presents an experimental study conducted using a modular flow-loop apparatus to evaluate flow diagnostics with Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) across simulated well scenarios. Dedicated simulators, including horizontal and vertical injection and production wells, enable repeatable emulation of subsurface dynamics such as steady-state and transient flow regimes, leak inflow/outflow, time-varying injectivity and productivity, and intervention responses. Each simulator incorporates programmable flow conditions with synchronized acquisition of DAS and DTS data, co-registered with reference pressure and flow instrumentation. In addition to passive sensing, we investigate active modalities that strengthen flow-signal detectability, reduce interpretation ambiguity, and increase confidence in physics-based flow profiling. In active DAS, low-frequency flow stimulation generates broadband harmonics that enhance spectral content and signal-to-noise ratio. For active DTS, a novel distributed anemometry approach uses the temperature response to a controlled, steady heat input to estimate the flow velocity profile. The results provide experimental validation and example self-learning flow allocation workflows for distributed sensing as a quantitative diagnostic tool for transient well dynamics. With high-resolution sensing, operators gain immediate insight into downhole flow phenomena, supporting on-the-fly data-driven adjustments to interventions and robust assessments of zonal performance in complex subsurface environments.

Abstract High-Frequency Torsional Oscillations (HFTO) present a major challenge when drilling hard formations, often leading to reduced performance and tool failure. This paper compares two modeling approaches for evaluating HFTO stability across the drilling system: a fast analytical criterion-based simulation and a detailed time-domain simulation using reduced-order modeling (ROM). Both aim to predict bit-induced HFTO excitation and rank bit designs accordingly. Both modeling approaches use a shared physics-based bit force model to compute torque response as a function of weight-on-bit (WOB), depth-of-cut (DOC), and RPM. The first method applies a damping-based criterion for rapid HFTO stability assessment. The second uses a physics-informed ROM to simulate dynamic responses over a wide range of operating conditions. Both incorporate BHA configuration via sub-models to generate torsional stability maps. Validation against lab and field data confirms their reliability and practical relevance. Experimental testing of ten 8½″ bit designs on a full-scale lab BHA showed that cutter and blade configurations can influence the HFTO-stable operating space by up to 40%. Both models successfully ranked bit designs while accounting for key BHA parameters such as motorization, damping tools, and inertia. The criterion-based model enables fast evaluation (under 5 minutes), making it suitable for early-stage design screening and real-time field use where speed is critical. It integrates well with automated drilling control systems to enhance rate of penetration and decision-making efficiency. In contrast, the ROM approach featuring axial-torsional coupling offers deeper insight into instability mechanisms and is best suited for thorough system validation prior to deployment, albeit with higher computational effort. This work introduces two complementary simulation frameworks that advance HFTO prediction and mitigation. The ability to rank bit designs without extensive experimental calibration marks a significant technical step forward, supporting more stable and efficient drilling operations in challenging environments.

Abstract The stress state of a Polycrystalline Diamond Compact (PDC) cutter during drilling is challenging to analyze due to the complex contributions from the rock-cutter interaction, drill bit design factors, drilling dynamics, and cutter manufacturing processes. Typical PDC cutter finite element analysis (FEA) models focus on either static mechanical loading from drilling or the residual stresses from cutter manufacturing. This work shows the importance of capturing the combination of stresses from cutter manufacturing, mechanical loading from drilling, and the thermal environment during drilling as well. This work presents an advanced FEA model that more accurately describes the stresses on PDC cutters during drilling thereby enabling better cutter designs and informed forensics. The model utilizes the thermomechanical properties of the cutter's diamond table and carbide substrate as well as its interface geometry. A Multiphysics sequential solver is employed to capture the stress evolution through the different states witnessed by the cutter from manufacturing to service loads both mechanically and thermally. Finally, the model can be extended to different cutter geometries and include worn conditions. The model results conform with different FEA studies describing individual cutter stress states such as residual stresses or mechanical loading. The usage of the Multiphysics sequential solver enables the superposition of the cutter states from different manufacturing and service conditions enabling better identification of the critical stress areas. For example, this new modeling approach provides a better correlation of cutter design to field results in terms of diamond table thickness. After sintering, the residual stress in the thinner diamond table is more compressive, which helps counteract the high cutting loads experienced in that region. In contrast, the thicker diamond table exhibits higher residual tensile stresses. This outcome contradicts the predictions of FEA incorporating mechanical loading only, which suggests that a thicker diamond table should experience lower tensile stress outside the cutting zone compared to a thinner one. This work is a step forward in the PDC cutters design and forensics. Coupling such a model with the drilling modeling and simulation tools will enable as accurate as possible FEA analysis to identify design challenges and/or material limitations.

Abstract There are numerous gas-condensate fields that are maturing with rising liquid levels around the wellbores which reduces gas production and escalates corrosion. Cost-effective approaches are needed to revive and prolong gas production. Foamers are among the most inexpensive methods to remove liquid loading. Combinational foamer and corrosion inhibitor products are used to prevent corrosion and enhance productivity. However, there are many difficulties in combining different production chemicals, especially to create a stable homogeneous product for high temperatures application. In this paper, the development of combination corrosion inhibitor - foamer products that have high temperature stability above 350°F and high flash point above 45 °C are described. The products have corrosion inhibition efficiency above 75% to protect mild steel under severe sour corrosion conditions up to 300°F and partial pressures of 100 psi CO2 and 100 psi H2S. Foaming performance in different liquid compositions is discussed. In addition, the selection of candidate wells for treatment with a newly created software is introduced. The software uses liquid loading equations and incorporates the reduction of surface tension and liquid density by the combination product. Calculations for field use of the product are presented.

Abstract The extraction and purification of helium from produced natural gas is well defined in conventional oil and gas production. Recent exploration has fostered development of wells in inert gas environments that are liquids deficient in comparison to conventional oil and gas extraction. During initial design and mitigation planning, theoretical corrosion rates predicted through historical models indicated a low risk of internal corrosion within the producing environment. Operating conditions consisting of high pressures in combination with condensed produced water and elevated CO2 concentrations were encountered once production began. Internal monitoring via visual and in-line inspection (ILI) found severe internal corrosion early in the life of the producing infrastructure, which resulted in extensive pipeline repairs that were completed in mid-2024. The increased economic investment fostered changes in both the mechanical and chemical corrosion mitigation practices employed throughout the field to be made. Increased pigging frequency, the application of a water-dispersible oil-soluble batch corrosion inhibitor and co-applying a continuous corrosion inhibitor into the gas stream has maintained the pipeline integrity of the repaired sections. Extensive field monitoring and the sharing of asset integrity best practices has led to the increased expansion of production in this unique environment that is rich in inert gases.

Abstract Our recent work on molecular evolution and population genetics postulated that individuals with a specific mutation exhibit a fluctuation in fitness, short for FSI (fluctuating selection among individuals), whereas the fitness effect of wildtype remains a constant. An intriguing phenomenon called selection-duality emerges, that is, a slightly beneficial mutation could be a negative selection (the substitution rate less than the mutation rate). It appears that selection-duality is bounded by two bounds: the generic neutrality where the mutation is neutral by the means of fitness on average, and the substitution neutrality where the substitution rate equals to the mutation rate. In addition, the middle point of generic neutrality and substitution neutrality is called the FSI- neutrality . An important problem is about the age profile of allele frequency, i.e., the arising timing of a mutation whose frequency in the current population is given ( the allele-age problem for short). Solving this problem under selection duality would help extend the standard coalescent theory that based on strict neutrality to a more general form under selection duality. In this paper, we studied the allele-age problem under selection-duality by the first arrival time approach and the mean age approach, respectively. Since the general solution of allele-age problem under selection duality is not available, we focused on solving the problem at the substitution neutrality (the up-bound of selection duality), the FSI-neutrality (the middle-point) and the generic neutrality (the low-bound), respectively. Our analysis results in an overall picture that the mean first-arrival age of a mutation at the substitution neutrality is theoretically identical to that at the FSI-neutrality, which is numerically close to that at the generic neutrality. For illustration, we calculated the mean age of nonsynonymous mutations in the human population and demonstrated that the estimated allele-age could be overestimated considerably when the effect of FSI was neglected.