PREDICTION AND TESTING (ASTM E-837-89) OF RESIDUAL STRESSES IN STRUCTURES (OPERATED IN SOHIC ENVIRONMENT) CAUSED BY WELDING

ABSTRACT The study and testing of the structural behavior of a failed pipe with a spiral weld seam was conducted. Our study and testing was part of a larger failure investigation to determine the influence of residual stress for initiation of hydrogen stress cracking. Finite element and structural testing methods were used to guide the study for determination of residual stresses. All properties used in our study were measured per ASTM A-370. The validation of the finite element model of the pipe was conducted against the test results per ASTM E-837-89. The difference in predicted and measured residual stresses was 3% at the ID of the structure. Due to the small differences in the results from analysis and testing, no correlation was required, and the test-validated finite element model was used to predict the total stresses due to the manufacturing processes and operational loads. Based on the validation results, one can conclude that the finite element technique is accurate for predicting residual welding stresses. The finite element technique, however, is far less time -consuming and thus less expensive method than mechanical testing for determining the residual stresses

Feasibility analysis of surface-to-reservoir electromagnetics for waterflood monitoring

Summary We analyze, by means of a synthetic model, the feasibility of detecting the electromagnetic (EM) field variations related to waterflood in a large Saudi Arabian Jurassic reservoir. We utilize a 3D structural reservoir model and derive the geoelectric parameters from careful analysis of well logs acquired at the Saudi Aramco Technology Test Site. The resistivity variations as a result of water flooding are derived using characteristic parameters and injection water salinity of the field. We model a geometry consisting of a radial surface galvanic source and four EM receivers located at the reservoir level. The full EM field is modeled in the time domain and the horizontal and vertical electric field (Ex and Ez) and horizontal crossline magnetic field (dBy/dt) components are interpreted and analyzed. Results indicate that all the modeled fields show substantial variations as a result of water saturation changes with field strength values above the noise level expected for EM sensors. The results will be validated next by modeling more complex and realistic 3D patterns of water saturation in the reservoir, as derived directly from reservoir simulation. Given that one of the modeled components is the vertical electric field, the electrical anisotropy of the overburden is expected to play a significant role in the response and will be taken into consideration in the next round of modeling. Modeling results also suggest that the type of borehole EM sensors currently available in the industry may not be adequate for surface-to-reservoir EM applications

Estimation of long-wavelength near-surface velocity and low-relief structural anomalies—Part I: A case history

Summary Undetected near-surface and subsurface velocity variations greater than an effective spread length produce false structures both in time and depth. The estimation of these variations rely on uphole measurements, high density shallow reflection data and sufficiently long offsets for subsurface reflectors. Despite inadequate near-surface velocity-depth measurements in the study area, we developed a strategy for the detection and estimation of both near-surface and subsurface long-wavelength velocity and low-relief structural variations. We chose two 2D seismic lines (dip and strike) over two existing low-relief fields in central Saudi Arabia, to demonstrate how the velocity-depth ambiguity problem is partially overcome by integrating the refraction delay time solutions derived from multiple refractors below the seismic reference datum with iterative pre-stack depth migration, residual analysis, and reflection tomography. We compare these results with the conventional isopach depthing method and discuss how this strategy improves the structural integrity of potential prospects. Even with the verification of the near-surface velocity and structural anomalies along the dip line and buried velocity anomaly along the strike line through forward modeling and flatness of depth image gathers, these models are non-unique. Based upon this case study, a new constrained tomographic algorithm has been developed which overcomes the above ambiguity and is discussed in Part II. Introduction In central Saudi Arabia, 2D seismic data is acquired along lines (greater than 70 km) over near-surface conditions which include different combinations of sand lenses, buried channels, leaching, outcropping formations, and in some areas the effects of a shallow unconfined aquifer. These variable near-surface conditions give rise to lateral velocity variations and thus to time anomalies of wavelengths of different scales, from as small as a cdp interval to much greater than a cable length. The base of weathering for short wavelength velocity variations is confined to several tens of meters below the surface and extends well below the seismic reference datum (SRD) for long wavelength lateral velocity variations. In the study area, the sparsely spaced and shallow uphole control points could not be used to generate a reliable 3D average velocity model because the base of weathering is well below the maximum uphole penetration depth and SRD

[ARAMCO Dhahran library collection 11208 EES] ٱلْمَمْلَكَة ٱلْعَرَبِيَّة ٱلسُّعُوْدِيَّة .الدِرْعِيّة. حي الطريف

[ARAMCO 11208 EES] Kingdom of Saudi Arabia, al-Dirʻiyyah, al-Turaif, eastern residential area, unidentified buildings, documented before 1970. The large building on the far right is called, however, the Palace of Muḥammad al Thunayān (ثنيان) ibn Sa'ūd; he was one of the brothers of Imām Muḥammad ibn Sa'ūd (d. 1765) and is the head of the Thunayān cadet branch of the royal family

Lucha por el transporte del petróleo en el Oriente Medio‎‎

Dibujo de Aristóteles OnassisPublicaciones: Signatura MH-80/53 correspondiente a la caja y sobre de la Colección Mundo Hispánico‎‎Título tomado de la revistaFirmado por R. RamosPublicado en Mundo Hispánico, n. 94 (año 1956, enero), p. 32Dibujo a tinta negra sobre papelIndicaciones para impresión a lápiz roj

What is AdBlue?

<p>AdBlue is a chemical compound that is safe for the environment. Its composition is roughly 32.5% pure urea and 67.5% deionized water. It is primarily used to lower the contaminants that desal vehicles' exhaust is assessed for. when the Selective Catalytic Reduction (SCR) system injects AdBlue into the exhaust of the vehicle. Hazardous nitrogen oxide emissions are transformed into safe nitrogen and water vapor by the SCR.</p><p> </p&gt

Experimental Study on the Transport and Improved Oil Recovery Mechanism of Submicron Particle Gel

Excessive water production could cause rapid decline in well deliverability and may lead to early well abandonment. Submicron polymer particle gel is a relatively new remedial treatment for excessive water production problems. This novel water control system can be adjusted according to formation pore throat sizes, particularly for deep profile control. However, current publications only introduced their physical properties and field applications. Moreover, no lab results have been reported about their transport behaviors and oil recovery improving abilities. This work investigated the transportation of a submicron particle gel system into porous media to block high permeability water flow channels. Coreflooding experiments on Berea sandstones were conducted not only to examine the water blockage mechanisms, but also to understand the potential improvement in oil recovery. Concentrations of submicron particle gel and brine are the two major factors that can potentially affect the efficiency of the water blockage and oil recovery improvement. Therefore, effect of these two parameters were thoroughly investigated in this experimental study. Meanwhile, to observe the in-depth transport of the submicron particle gel, the core holders with multiple pressure taps were used to monitor pressure drop at different sections and identify where the particles were transported. In the first part of the research, three different submicron particle gel concentrations were involved. The injection volumes of submicron particel gel dispersion were kept same in all coreflooding experiments. Result shows that the particle gel can transport deeper into the core, yields better impact on the efficiency of water blockage and result in higher oil recovery improvement when the gel concentration was higher. The second part of the research studied the impact of brine concentration. With difference in salinity environments, submicron particel gel had different swelling ratios and strengths: swollen particles were bigger and weaker with lower salinity. Unlike previous research, submicron particle gel was injected until a stable injection pressure in all sections of the core. Results indicate that high salinity environments could result in better plugging efficiency however low salinity environments could result in better oil displacement efficiency. The reasons behind the results have been analyzed by evaluating the submicron gel physical and rheology properties in lab. By studying the impacts of these two factors, this work provides a better understanding of submicron particle gel transportation and oil recovery improvement mechanisms, which is of major importance for an optimized design of a successful submicron particle gel treatment

Full Wave Form Inversion for Seismic Data Full Wave Form Inversion for Seismic Data Problem presented by iii+12 pages B-i Full Wave Form Inversion for Seismic Data KSG 2011 Report coordinator

Executive Summary In seismic wave inversion, seismic waves are sent into the ground and then observed at many receiving points with the aim of producing highresolution images of the geological underground details. The challenge presented by Saudi Aramco is to solve the inverse problem for multiple point sources on the full elastic wave equation, taking into account all frequencies for the best resolution. The state-of-the-art methods use optimisation to find the seismic properties of the rocks, such that when used as the coefficients of the equations of a model, the measurements are reproduced as closely as possible. This process requires regularisation if one is to avoid instability. The approach can produce a realistic image but does not account for uncertainty arising, in general, from the existence of many different patterns of properties that also reproduce the measurements. In the Study Group a formulation of the problem was developed, based upon the principles of Bayesian statistics. First the state-of-the-art optimisation method was shown to be a special case of the Bayesian formulation. This result immediately provides insight into the most appropriate regularisation methods. Then a practical implementation of a sequential sampling algorithm, using forms of the Ensemble Kalman Filter, was devised and explored