Erosion Study for a 400-MMcf/D Completion: Cannonball Field, Offshore Trinidad

The Cannonball Field is a one Tcf gas condensate development offshore Trinidad producing at a sustained rate in excess of 800 MMcf/D from three wells. The completion design selected was 7⅝ inch production tubing with an open-hole gravel pack. The initial well (CAN01) has produced at 333 MMcf/D. These rates are higher than typically experienced which has raised concerns concerns about the resultant potential for metal erosion. As a result, a rigorous erosion study was initiated. The objective was to quantitatively evaluate erosion at various rates over the life cycle of the well to appropriately design the completion and select the appropriate materials. The erosion nodes within the completion - changes in flow direction (e.g. a tee such as in the wellhead) and/or flow constrictions - were identified as: the tree; a landing nipple profile near the surface; and a formation isolation device (FID) positioned in the gravel pack assembly. The key parameters were defined as particles of sharp sand, with a diameter of 50 microns, at a concentration of 0.1 lbs/MMcf. Erosion rates were calculated using the erosion model - Sand Production Pipe Saver (SPPS) - developed by the Erosion/Corrosion Research Center, University of Tulsa, USA. Erosion rates were calculated over the life cycle starting at initial rates of 280 and 400 MMcf/D. Erosion rates were also calculated with and without a liquid film (a protective layer on the pipe wall that can reduce the erosion rate). Erosion results (without a liquid film) at all nodes exceeded BP's erosion limit; however, the erosion results with a thin liquid film were mostly below the company's erosion limit. Determination of the presence and thickness of the liquid film was critical. A multi-phase pipeline simulation calculated that a sufficient liquid film would exist at all critical areas. Erosion of the tree was further assessed by computation fluid dynamics (CFD) models, which identified several hot spots; thus, additional cladding of all flow-wetted surfaces and rounding of the outlet corner was required. The Cannonball completion design, including the tree, was determined to be capable of sustained rates up to a maximum 400 MMcf/D. The three (3) well development, where initial rates have been as high as 333 MMcf/D, has been on production for several years without any erosion issues.

Dust reduction in abrasive jet micro-machining using liquid films

Phase change driven heat transfer has been the topic of interest for a significantly long time. However, in recent years on demand sweating boosted evaporation which requires substantially less amount of the liquid medium has drawn attention as a possible way of increasing/supplementing heat transfer under convective conditions where the convective heat transfer coefficient has already reached its maximum value as well as where dry cooling is a desired objective. In this study, a numerical study is conducted to obtain insight into the ‘hybrid’ system where evaporation and convection both contribute to the heat transfer effect. The system modeled consists of evaporation of thin liquid (water) film under a laminar flow condition. The mathematical model employed consists of coupled conservation equations of mass, species, momentum and energy for the convection-evaporation domain (gaseous), with only mass and energy conservation being resolved in the liquid film domain. The evaporative mass flux is obtained from a modified Hertz-Knudsen relation which is a function of liquid-vapor interface temperature and pressure. A two-dimensional rectangular domain with a pre-prescribed thin liquid water film representative of an experiment is simulated with the developed model. The thin rectangular liquid film is heated by uniform heat flux and is placed in the convection-evaporation domain with an unheated starting length. A moving boundary mesh is applied via the“Arbitrary Lagrangian-Eulerian” technique to resolve the receding liquid interface resulting from evaporation. The prescribed relative displacement of the moving interface is calculated from the net mass flux due to evaporation and is governed by the principle of mass conservation. Simulations were conducted over a range of Reynolds number, heat flux conditions and liquid film thickness. The numerical predictions indicate that under convective-evaporative conditions the overall heat transfer coefficient increases significantly (∼factor of a five) in comparison to the purely forced convection scenario. An increase in the heat transfer coefficient is observed with Reynolds number and vice versa for film thickness. A critical Reynolds number is identified beyond which the heat transfer coefficient does not continue to increase significantly rather tends to plateau out.

The oil industry transport the crude oil, but with entrained solid particles. Throughout the production operations of the upstream petroleum, crude oil as well as sand particles corroded from the zones of the formation are regularly conveyed through pipes as a mixture up to the well heads and among well heads and flow stations. In this study, a three-dimensional CFD (Computational fluid dynamics) model has been developed that describes a turbulent transport of solid sand particles as well as crude oil through elbows to predict the erosions rates, where various physical aspects have been combined together including flow turbulence, particle tracking, and erosion simulation. The model has been used to investigate the different parameters that effect for crude oil and sand particles on the erosive wear rate on the pipe walls. Where, the parametric studied for crude oil are viscosity, density, velocity and temperature, also, the parametric studied for sand particles are parti-cles size, particles density and mass flow rate. Therefore, the investigation included evaluated the erosive wear rate on the pipe walls with different parametric studding by using numerical method with CFD technique. This model includes simulation of the three dimensional for turbulent flow, sand particle, and erosion rates modeling. Where, used three methods to evaluating the erosive wear rate on the pipe walls, The Finite Model, The Erosion Rate (E/CRC) Model and The Erosion rate (DNV) Model. Also, in this work can be prediction of the ero-sion position occur on the pipe wall with various parametric effect. Then, the results presented shown that the rate of erosion is increase with increasing the friction between the oil and pipe wall by variable the parametric of crude oil or sand particles. Also, the results are shown that the position of erosion variable dependent on the parametric of oil and sand. Finally, the work shown that the CFD technique is good tool can be used to evaluating the erosion rate and erosion position on pipe wall with various crude oil and sand particles parametric.

Circulation pressure washing is one of the least understood practices in open hole gravel packing. If indiscriminately applied, it causes packing. If indiscriminately applied, it causes early gravel pack failures as well as considerable loss of productivity. This paper presents the results of a model study of gravel placement and pressure washing operations in open hole gravel packs. A movie will be presented to demonstrate gravel placement during a gravel packing operation and the interaction between gravel and formation during subsequent pressure washing. pressure washing. WHAT IS PRESSURE WASHING? Pressure washing, as the word implies, involves a high velocity jetting of fluid through the openings in the retaining liner. This jetting is usually confined to a short vertical interval, separated by two opposed swab cups. If washing fluids are returned to the surface, we call it circulation pressure washing. CIRCULATION PRESSURE WASHING Circulation pressure washing is a common practice routinely applied by many gravel packing practice routinely applied by many gravel packing companies and operators. Unfortunately, it is one of the most misunderstood and misapplied "arts" of the oil industry. A growing body of evidence indicates that it is not only one of the main reasons for early open hole gravel pack failures, but it is also a main cause of an unnecessary loss of oil production. production. In order to shed a little light on the pressure washing of the open hole gravel packs, and pressure washing of the open hole gravel packs, and possibly to clear up the many misconceptions, we possibly to clear up the many misconceptions, we designed and built two visual models. A photograph of the second model is shown in FIGURE 10. photograph of the second model is shown in FIGURE 10. Our models were designed solely to demonstrate visually the near-borehole conditions existing during pressure washing of open hole gravel packs. No quantitative measurements were obtained of permeability changes during pressure washing, and permeability changes during pressure washing, and our results are reported qualitatively from visual examination. Furthermore, this paper will not deal in any depth with circulation pressure washing of perforations for "inside" gravel packing. Although perforations for "inside" gravel packing. Although our study showed detrimental effects from pressure washing of open hole gravel packs, pressure washing of perforations is a very good and very necessary practice under the proper conditions. However, for practice under the proper conditions. However, for successful results with this method, super clean fluids must be used, and the perforations must be cleaned prior to gravel packing. WHEN AND WHERE IS PRESSURE WASHING USED? Most operators and service companies use pressure washing when they suspect that only a part of pressure washing when they suspect that only a part of the theoretical volume of gravel is placed behind the screen at the time of screenout. Some operators pressure wash initially, to insure a full pack, pressure wash initially, to insure a full pack, others claim that an open hole gravel packed well cannot produce properly and satisfactorily without pressure washing. pressure washing. Pressure washing received its strongest impetus when operators had to gravel pack some high angle holes from offshore platforms and frequently suffered premature screen-outs. Pressure washing solved-the problem of gravel placement in high angle holes and became a standard field practice. Its use spread throughout the world, and practice. Its use spread throughout the world, and today it is often routinely applied even in relatively straight and simple holes. PRESSURE WASHING TN HIGH ANGLE HOLES PRESSURE WASHING TN HIGH ANGLE HOLES In high angle holes, 50 deg. or more from vertical, PACKING OCCURS FROM TOP DOWN, RATHER THAN FROM PACKING OCCURS FROM TOP DOWN, RATHER THAN FROM BOTTOM UP as is the case in vertical holes. Consequently, when high angle holes are packed using standard packing procedures, the pack usually bridges first in the top 10–20 feet of the interval to be packed.

In recent years, several gas-phase odor biosensors have been developed. Sensitive cells and multiple sensing elements were investigated for enhancing the performance of those biosensors. The thickness of the liquid layer that covers the cells, however, has rarely been so far explored. Recently we utilized the feedback control method to maintain a constant liquid film. Now we intended to step further about the alteration and estimation of this liquid film. Here, we developed a gas phase odor biosensor with variable liquid film thickness. The liquid layer thickness change was reflected as the impedance change between two electrodes. Thinner liquid film always resulted in greater response and faster peak time. For realizing such a thin liquid film state, withdrawing the buffer solution step by step was more preferred. Furthermore, the sample concentration dependency curves under normal and thin liquid layer conditions proved thin liquid film improved response evidently. Moreover, the weakened stability caused by thin liquid film was explained. Finally, we calculated the liquid film thickness according to the feedback control signal and validated the estimation result by manual operation. It revealed a steady liquid film thinner than 100 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> was implemented in this system. This study demonstrated the advantages of thin liquid layer and provided an access to estimation and fine adjustment of liquid film thickness in gas phase odor biosensors.

Molecular dynamics data-driven study of leidenfrost phenomena in context to liquid thin film phase transformation

Achieving complete and efficient gravel packing is the primary objective when tasked to install an effective sand control completion. This paper describes the challenges faced during the selection, design, planning and execution phases of the open-hole horizontal gravel pack completions in the "L" field, offshore Republic of Congo. The open hole gravel packs (OHGPs) targeted the most prolific sand to ensure production objectives were achieved with the benefit of a gravel-pack completion. The operator completed two OHGPs with alpha/beta technique for the sand face completion utilizing concentric annular pack screen (CAPS), wire-wrap screens, and a service tool permitting post-gravel pack filter cake clean-up treatments. The accurate selection, modeling, and evaluation of sand control techniques were crucial for completion and production optimization, as well as risk minimization. The service approach had traditionally leveraged upon industry rules of thumb and previous experience, but as the reservoir section length increased and completion configuration became more complex, the error margins tightened and the cost of failure increased such that a more robust design approach was needed. This paper addresses several key factors that must be considered carefully when installing a successful gravel pack completion. The dynamic pressure management becomes critical to maintain the bottom hole pressures within a required range for the successful implementation of the gravel pack. Other factors include designing an optimal screen-wash pipe annulus ratio during alpha-beta wave packing, an optimal alpha wave height, and the use of multiple beta wave packing rates. Results from the preliminary modelling of the gravel pack pumping provided an accurate estimation of the maximum and minimum anticipated pumping rates and pressures. These parameter estimates were generated for the workstring design scenarios and provided guidance for the planned pumping rate adjustment during the gravel packing execution phases. The gravel packed wells achieved pack efficiency greater than 100% based on an estimated 8.5-in. diameter OH. Post completion multi-rate tests concluded potential productivity exceeding the operator's expectations. This paper describes the lessons learned and best practices developed for offshore Congo open-hole gravels packs, which have a very challenging well completion and reservoir scenario. Several proven completion practices are reviewed, with a critical examination of the application of these scenarios for future completion operations in this difficult operating environment. This applied methodology has made significant impact on future field development and increased the production expectations for the asset.

This paper highlights the new drilling and completion technologies used in the delivery of the company’s first successful horizontal open hole gravel pack (OHGP) in the deep-water Gulf of Mexico (GoM). The well was drilled and completed with well performance exceeding the planned objectives. A new drilling fluid system was needed to address the high depletion, minimize formation damage, and manage the wellbore stability challenges associated with depleted horizontal drilling stress anisotropy. A brine-based system inclusive of a reservoir drill-in fluid (RDIF), solids free screen running pill, and displacement push pill, were qualified. Managed pressure drilling (MPD) was employed to manage the drilling of depleted sands, and managed pressure cementing (MPC) was used for cementing across narrow frac gradient (FG) windows, a new application for the company. New real time drilling surveillance was also applied to allow for trajectory optimization and maximining the open hole (OH) length. For the completion, a new high temperature gravel pack (GP) carrier fluid was developed to meet the high reservoir temperature and pressure requirements. This GP fluid was also designed to break on surface using an optimized breaker system, allowing for full capture with zero discharge. The sandface completion system included a new to GoM shunted wire wrap screen (WWS), y-manifold, and new lower completion hardware including an anti-swab GP service tool. New completion open hole displacement and GP procedures, to include a new skid-based GP pumping technique, were also implemented successfully.

Drainage kinetics, thickness, and stability of water-in-oil thin liquid emulsion films obtained from asphaltenes, heavy oil (bitumen), and deasphalted heavy oil (maltenes) diluted in toluene are studied. The results show that asphaltenes stabilize thin organic liquid films at much lower concentrations than maltenes and bitumen. The drainage of thin organic liquid films containing asphaltenes is significantly slower than the drainage of the films containing maltenes and bitumen. The films stabilized by asphaltenes are much thicker (40-90 nm) than those stabilized by maltenes (∼10 nm). Such significant variation in the film properties points to different stabilization mechanisms of thin organic liquid films. Apparent aging effects, including gradual increase of film thickness, rigidity of oil/water interface, and formation of submicrometer size aggregates, were observed for thin organic liquid films containing asphaltenes. No aging effects were observed for films containing maltenes and bitumen in toluene. The increasing stability and lower drainage dynamics of asphaltene-containing thin liquid films are attributed to specific ability of asphaltenes to self-assemble and form 3D network in the film. The characteristic length of stable films is well beyond the size of single asphaltene molecules, nanoaggregates, or even clusters of nanoaggregates reported in the literature. Buildup of such 3D structure modifies the rheological properties of the liquid film to be non-Newtonian with yield stress (gel like). Formation of such network structure appears to be responsible for the slower drainage of thin asphaltenes in toluene liquid films. The yield stress of liquid film as small as ∼10(-2) Pa is sufficient to stop the drainage before the film reaches the critical thickness at which film rupture occurs.

The flow and heat transfer of the oblique impact of a droplet on a stationary liquid film with various dimensionless thicknesses (01.0–0.5) are investigated experimentally and numerically. A superhydrophobic guideway is used to create the oblique impact of a droplet, which causes subsequent asymmetric crown structure and splashing. The thermal level set method is employed to capture the deformation and heat transfer of warm droplets' oblique impact on a cold liquid film. A parameter study of the effect of Weber number, oblique angle, and liquid film thickness on geometrical characteristics and wall heat flux is carried out. The results show that in the downstream direction, during the crown rising period, the radius is independent of the normal Weber number but increases for a larger tangential Weber number and a thinner liquid film. The maximum downstream crown height increases with an increase in the Weber number and exhibits a non-monotonic trend with the liquid film thickness. The heat transfer rate between the liquid film and surface decreases with larger oblique angles and thicker liquid films while having a poor dependence on the Weber number. In addition, the critical oblique angles for prompting splashing at different liquid film thicknesses are presented. Finally, modified thermodynamics models and splashing thresholds for the liquid film are developed to further enhance the understanding of aircraft icing.

Summary An increasing number of horizontal wells requiring sand control are being gravel packed, particularly in deepwater and/or subsea environments in which completion reliability is paramount because of the prohibitively high cost of remediation. Tophole sections in many of these wells are being drilled with oil-based (OB) fluids, with the common practice of switching to water-based fluids when the reservoir drilling starts. In the last several years, some operators started using OB drilling fluids in the reservoir section as well and gravel packed them with water-based fluids. In some cases, these practices required running predrilled liners in OB fluids and subsequently displacing to water-based fluids before running in hole with the sandface screens and gravel packing. In other instances, screens could be run in hole with OB fluids in the wellbore, and gravel packing could be performed with water-based fluids. In both cases, the presence of reactive shales and/or water-sensitive productive zones can introduce serious concern, in the event that carrier-fluid losses occur into the formation during gravel packing. Although a base-oil or diesel can be used as a carrier fluid, low density of the base oil limits such applications to low-pressure/depleted wells. In this paper, we present a case history of the first successful application of drilling and completing in an all-oil environment, using a reversible OB reservoir-drilling fluid (RDF) (the filter cake of which reverses wettability from oil to water when exposed to an acidic fluid) and an OB gravel-packing fluid. The carrier fluid used in this application included a filter-cake cleanup solution in the aqueous internal phase of the OB carrier fluid, extending the application of simultaneous gravel-packing and cake-cleanup processes that have been successfully practiced in water-based-fluid environments to OB systems. The subject application was in a high-rate gas field located offshore Trinidad, with anticipated production rates in excess of 150 MM scf/D per well. Presented in the paper is the drilling and completion selection methodology based on extensive laboratory and yard testing, along with the details of the completion and recommendations for future applications based on lessons learned. A direct comparison of the all-oil drilling and completion process to water-based drilling and completion is also presented based on a case history from the same field.

Numerical prediction of solid particle erosion under upward multiphase annular flow in vertical pipe bends

The effect of liquid film evaporation on flow boiling heat transfer in a micro tube

Flow boiling in micro channels is attracting large attention since it leads to large heat transfer area per unit volume. Generated vapor bubbles in micro channels are elongated due to the restriction of channel wall, and thus slug flow becomes one of the main flow regimes. In slug flow, sequential bubbles are confined by the liquid slugs, and thin liquid film is formed between tube wall and bubble. Liquid film evaporation is one of the main heat transfer mechanisms in micro channels and liquid film thickness is a very important parameter to determine heat transfer coefficient. In the present study, liquid film thickness is measured under flow boiling condition and compared with the correlation proposed under adiabatic condition. The relationship between liquid film thickness and heat transfer coefficient is also investigated. Pyrex glass tube with inner diameter of D = 0.5 mm is used as a test tube. Working fluids are water and ethanol. Laser focus displacement meter is used to measure the liquid film thickness. Initial liquid film thickness under flow boiling condition can be predicted well by the correlation proposed under adiabatic condition. However, measured liquid film thickness becomes thinner than the predicted values in the cases of back flow and short slugs. These are considered to be due to the change of velocity profile in the liquid slug. Under flow boiling condition, liquid film profile fluctuates due to high vapor velocity and shows periodic pattern against time. Frequency of periodic pattern increases with heat flux. At low quality, heat transfer coefficients calculated from measured liquid film thickness show good accordance with heat transfer coefficients obtained directly from wall temperature measurements.