Aluminium alloys are being widely used in naval applications owing to their excellent corrosion resistance and high formability characteristics. One of the most popular naval components is the tarpedo blade which makes use of forged aluminium alloy followed by anodizing surface treatment for corrosion protection. In recent years, there have been few attempts to replace the conventional aluminium alloys by their composites for the tarpedo blade applications. Literature review clearly says that CeO2 (Ceria) coating on aluminium and aluminium composites enhances their corrosion protection in aggressive marine environment. Further, there are reports suggesting that combination of CeO2 and TiO2 do yield better corrosion protection. However, there is no information on the work related to development of hybrid ceramic reinforced aluminium alloy matrices with CeO2 and TiO2 as particulate reinforcements for potential naval applications. In the light of above, the present work focuses on the development of novel Al6061-CeO2-TiO2 hybrid metal matrix composite by stir casting route followed by hot extrusion with an extrusion ratio of 8:1 at a temperature 550 °C and hot forging at 475 °C. The developed forged hybrid composites and the matrix alloy have been evaluated for microstructure, micro hardness and slurry erosion wear tests as per the ASTM Standards.

In recent times, several machine learning algorithms have been utilized to analyze massive amount of data and provide fast and effective smart solution. To monitor the saturation over time, reservoir saturation tool is run in each well to provide the cased hole saturations. A single well may have as many has 15-20 runs over time which provides an estimate of present saturation, depletion across reservoirs or any other changes in saturation profile to EOR system in place and its impact. This paper demonstrates the idea of the use of machine learning algorithm to perform a time lapse saturation analysis and present a saturation forecast based on class-based machine learning combined with the time series modelling using multiple time lapse runs in a single well for a field. The first step involves using an unsupervised class-based machine learning model that classifies the input petrophysical data into set of classes with distinct similarity. The next step of the workflow involves using time series modeling on each of the obtained classes. Different methods were studied and eventually "Prophet" was used for time series modeling to forecast saturation over time. A way forward and game changer is propagating the classes to multiple wells with multi runs and predict the changes in saturation and pressure for a formation across a field to make holistic interpretation. Reversing the time series modeling can also provide an estimate of OH conditions and original hydrocarbon in place. The use of CBML and time series modelling for petrophysical saturation evaluation will open new doors to understanding of fields already under production and introduce smart decision-making capabilities. The idea presented in this paper can be implemented in different fields across the globe with different formation settings and EOR system in place and can be further advanced in terms of providing deep insight and interpretation like forecasting the change in reservoir pressure.

Temperature logs have been used to monitor producing wells since the early 1930s. Normally, analysis of the temperature log is viewed as secondary to that of the spinner flowmeter, which gives flow velocity directly, and temperature is conventionally used only as an indicator of fluid entry/exit with the production logging tool (PLT). The main disadvantage of the PLT is that if spinner flowmeter data are not good due to tool problems, then flow quantification is jeopardized. Additionally, in recent years, the cost of production logging has increased considerably because many wells are now drilled horizontally through the reservoir, and the PLTs must be conveyed on coiled tubing or well tractors, and, in some cases (subsea wells), even this may not be possible. Consequently, alternative technologies become viable if they can be used for flow quantification using just temperature data. This paper presents a new flow quantification model using temperature data acquired using production logging or a distributed temperature sensor (DTS) system. The model presented in this paper can handle multiple production zones with their zonal fluid properties as input to give corresponding zonal flow rates as output. The said model is applicable for single-phase oil and gas producer wells as well as water injection wells in both onshore and offshore environments. There are two modes of flow calculation for each answer product-steady state or transient. The model is integrated into easy-to-use software, and it has options for forward simulation as well as optimization. The forward simulation calculates temperature distribution along the wellbore for any given production profile, which is critical for model calibration for any reservoir. After the model has been validated for a reservoir, it can be used for zonal flow quantification using any temperature survey. The objective of the optimization option is to allow the user to fit the model output temperature curve to a selected temperature curve by means of a genetic fitting algorithm that will adjust one or two user-selected reservoir parameters, such as permeability, pressure, skin, gas-oil ratio (GOR), temperature, or water-cut, until a fit is achieved. The model has been extensively tested against synthetic, literature and field examples and good agreements have been obtained, confirming the robustness of this novel approach.

The Gyda field in the North Sea operated by Repsol was proven in 1980 and the platform started producing in 1990. In June 2017, the Norwegian authorities approved the decommissioning plan for the Gyda field. The decommissioning scope included the permanent plugging of 32 wells in the field. Decommissioning is estimated to cost several hundred million dollars and is expected to finish in 2022. As per the NORSOK standards, each well needs to have confirmed barriers to isolate inflow zones, both for preventing from flowing to the surface and hindering crossflow between them. Cement and creeping formation are both considered to be potentially effective barrier elements. However, the criteria and verification methods used to confirm formation creep and cement as barrier elements are different and hence require an innovative interpretation technique which is presented in this paper. As per the regulations and standards, it is critical not only to evaluate the quality of the circumferential bond for cement and formation creep but also to determine their respective bond length. The most important measurement to accurately determine those criteria in each well is through the ultrasonic and flexural attenuation tool. However, interpretation to differentiate formation creep from cement presents challenges, especially when they have similar ultrasonic properties. Quite often, they coexist at the same depths on different sides behind the casing. Barrier evaluation becomes even more challenging with added complexities such as borehole mud settling due to high deviation, high eccentricity, casing damage, or presence of a microannulus. This paper discusses the techniques and interpretation methods used to accurately evaluate barrier elements, differentiate between cement and formation creep, estimate the tops of cemented areas, and eliminate complex challenges posed by mud, deviation, eccentricity, and wet microannulus sections. Successful and accurate determination of the potential presence and location of annulus barrier elements has been fundamentally important for Repsol to meet the regulatory requirements. A special interpretation technique was established using integrated data evaluation to differentiate creeping formation from cement. This technique successfully determined accurate barrier intervals, helping to meet all the regulatory requirements. The processes and methods have been audited and evaluated by the Petroleum Safety Authority Norway.

Casings can deform over the life of the well due to various reasons such as changing stress regimes, geological fault and fractures causing pinching, pressure differential created due to production, increased pressure due to injection, squeezing formations such as shale and salt, etc. A detailed casing deformation evaluation can provide insights to the operators in correlating the deformation to suitable reasons in their field. There are various methods to evaluate the innermost casing or tubing using ultrasonic and mechanical caliper measurements but there is no technology available to evaluate outer or second casing deformation without first retrieving the inner casing or tubing. This work introduces and encapsulates the novel methodology of transforming the outer or second casing third interface echo (TIE) response, obtained by advanced ultrasonic and flexural measurement inside innermost casing or tubing, into a 3D wellbore view to suitably visualize and analyze the outer or second string deformations. The work involves measuring the azimuthal radius and thickness of the innermost casing with the ultrasonic evaluation technique and computing the azimuthal annular distance between the two casings using the flexural wave TIE arrival time and its velocity in the annular fluid. The computed values are then combined to generate an array of azimuthal internal radius values of the outer or second casing and is finally converted into a 3D wellbore image for better and straight-forward visualization. To validate the methodology, a shop inspection test (SIT) was carried out where the dimensions of the inner and the outer casing were precisely measured with a mechanical caliper tool. Following that, ultrasonic and flexural measurement tool was run inside the innermost casing to obtain the response of both casings. The comparison showed a close match between the actual values and the measurements. Also, the 3D wellbore shape clearly showed the geometry of the outer string validating the methodology used in the creation of the 3D shape. The work can enable the operators to carry out time lapse outer string analysis on a periodic basis to give them early indications of any deformation in the outer or second string. This novel technique or methodology also has valuable application in plug and abandonment (P&A) where the inner tubing and casing retrieval can be hindered due to outer casing deformation. This technique can also help in designing the right drilling BHA for sidetracking based on the minimum ID of the outer pipe through which slot recovery or side-track has to be performed.