Advanced Technologies Used in Sand Control Completion

The techniques applied to control down-hole sand production have not changed for very many years. Almost every sand control solution involves the installation of a pipe-based filter that is either gravel packed or left as a "stand alone" screen. Gravel packing has evolved over more than 70 years, but still involves complex fluid and gravel pumping operations. Standalone screens, while being operationally very simple, do not support the formation, leading to a number of well reliability and production issues. Expandable sand screens were developed to overcome the shortcomings of both existing techniques, while also providing some unique benefits. The first commercial application of this technology took place in January 1999. Since then, their use has spread quickly to all parts of the world and in many diverse applications. As of November 2000, over 23,000ft of expandable sand screen had been run in over 25 applications. However, its introduction and acceptance into the U.S. has been slower in coming. It was not until early in 2000 that Chevron decided to complete its West Delta 117 field, well G- 7 S/T1 sidetrack, using expandable sand screen for sand control, thus making it the first such completion in the Gulf of Mexico This paper will provide a brief overview of expandable sand screen, its construction and advantages and will describe some of the issues addressed in this well completion. It will provide details of the installation procedure, the fluids employed and well production results achieved. It will conclude that the use of expandable sand screen as an alternative to conventional sand control methods in the Gulf of Mexico is viable. Background Field and well history. The West Delta 117 Field was discovered in 1962 and has since been developed by Chevron with over 100 wells drilled in the field. The pay sands are stacked deltaic deposits from 4900' to 14,500' and range in age from early Pleistocene to late Miocene. Sand control is installed in most wells in the field to address historical sand control problems. Objectives of sidetrack and re-completion. In May 2000, the OCS-G 9690 G-7 S/T1 well was drilled as an extended reach well to a seismic bright spot in the B-1 Sand at 4865' TVD. One other takepoint in the B-1 Sand had successfully produced gas in a separate fault block with a high rate water pack installed for sand control. The G-7 S/T1 well logged 16' corrected gas on water. Initial appraisal indicated that completing this well with a conventional gravel pack would not generate the best economic solution and that a completion with stand alone screens would not be sufficiently durable to assure a producing life with adequate longevity. Expandable sand screen offered the ability to control sand production without a frac-pack, but also promised to overcome the plugging and erosion problems of stand-alone screens. Further, the elimination of the frac-pack brought the project into economic reality by lowering the initial cost as well as reducing the risk of early water production compromising gas production.

Sand production is major problem for the oil and gas industry and solutions to this problem is a continuous process as new challenges arise with time. Various sand control methods have been proposed for tackling the sand production challenge, and research and experience have shown that the use of mechanical sand control methods are more suitable, with gravel packing being the most effective. Gravel packs are proven to be an effective mechanical sand control technique, and a good gravel pack completion design is of great importance to exclude sand from the wellbore while enhancing well productivity. Implementation of sand control by gravel packing in the Niger Delta is usually found to require importation of commercial gravel for the purpose of sand control which is a challenge in terms of high purchasing and transportation costs with import taxes. A solution is presented in this study which involves sourcing for gravel locally and investigating its suitability for sand control by gravel packing. Locally sourced gravel was compared with commercial gravel using sieve analysis and results showed that the locally sourced gravel closely met the requirements of the commercial gravel depicted by slot widths that are close to that obtained by the commercial gravel. Based on the results of this study, favorable performance is expected when locally sourced gravel is used for sand control by gravel packing in unconsolidated formations in the Niger Delta. It is recommended to source for different gravel types from different locations and evaluate using sieve analysis and Laser Particle Size Distribution Analysis to determine suitable gravel types for these type of formations.

Sand production has been highlighted as one of the critical challenges for Zawtika Project. Throughout the years of field experiences, sand production management has brought up many challenges, especially in terms of field potential sustaining, well productivity and investment justification. Alternative sand control technique is one of the keys to overcome these challenges with continuous improvements driven by lessons learnt. Chemical Sand Consolidation (CSC) is the chemical sand control technique using the resin to bond the formation grain and strengthen the formation strength whereas Thru-Tubing Gravel Pack (TTGP) is retrofit sand control method, which the sand control principle is similar to conventional Cased-Hole Gravel Pack (CHGP), but can be installed in a smaller completion size. In Zawtika existing development phases, almost 150 zones of sand producing intervals are handled by CHGP completion design. In addition to CHGP, these mentioned alternative sand control techniques have been successfully implemented in 3.5-inch-tubing monobore completion for selected deep reservoir intervals after some degree of depletion. Field trial of CSC and TTGP had been implemented during 2019-2020 with 5 reservoirs in 7 monobore completion wells (4 CSC wells and 3 TTGP wells). All wells showed positive results with no sand production from the post-job production; and with a reasonable increase in Maximum Allowable Sand Free Rate (MASR). Based on well performance monitoring until early of 2022, all 3 TTGP wells as well as 3 CSC wells no longer have any sand production issue. Nevertheless, only 1 CSC well with water production history record prior to CSC implementation shows poorer performance on sand production prevention. Following the positive results of TTGP from the previous campaign in term of sand production prevention and well life extension, 8 more TTGP well candidates have been implemented in early of 2022. At the early phase of production, sand free production has been observed for all wells with 51 mmscfd incremental MASR. With all aspects of technical and fiscal evaluation proven to be successful, sand retention and production performance of CSC and TTGP are continuously monitored to confirm long-term performance efficiency for full application in the future. Zawtika sand management strategy through alternative sand control completion has been improved upon accumulated lesson learns and production experiences. The lesson learns and experiences from both operation and well performance monitoring will be integrated for further improvement for the next implementation phases. Maximizing gas potential through alternative sand control methods is also believed to be the cost-effective approach which strengthens PTTEP's competitive performance.

In some Persian oil fields hydrocarbon recovery is mainly from sandstone reservoirs and sand production is a major problem in these fields. Main reason of sand production in these reservoirs is due to unconsolidated sandstone layers. The common method to decrease this problem is achieved by installing mechanical sand control systems. Previously, some techniques of sand control have been used in Persian oil fields, such as gravel packing, slotted liner and chemical consolidation. The results which have been obtained through these methods are not remarkably good enough in some cases. Expandable sand screen (ESS) is a new technique in sand control that can result in lower skin and consequently improves reservoir inflow performance. Field tests in various conditions have shown very satisfactory results in both open and cased hole applications. This paper will discuss economic aspects of ESS and analyses well pressures. In addition it provides ESS comparison with other sand control systems through real cases and well modeling. Finally, it talks about the candidate selection step and its significance on ESS performance.

International field trials have demonstrated that sand production and control are crucial issues that need to be addressed and resolved to achieve the commercial exploitation of natural gas hydrate (NGH). The objective of this study is to investigate sand migration and control in sediments with different particle size distributions during depressurization-induced hydrate exploitation. A 50PPI (pores per linear inch) polyurethane foam was chosen as the sand control material to further explore its performance under conditions closer to actual field reservoirs, which is the continuation and extension of previous investigations. Experimental results confirm that the 50 PPI polyurethane foam demonstrates good sand control effectiveness for reservoirs with a median particle size (D50) of quartz sands ranging from 10 to 100 μm, even under material extrusion deformation. Under comparable reservoir conditions, finer and more heterogeneous sediments increase sand control requirements. Meanwhile, no definitive correlation between internal sand migration and actual sand production was observed. In reservoirs with fine quartz sand, sand production manifests as consolidated sediment migration after hydrate exploitation, while heterogeneous quartz sand reservoirs undergo significant internal changes before and after the NGH exploitation, accompanied by a evident decrease in gas production rate. Based on the experimental study, a theoretical framework for sand migration and production mechanisms during NGH exploitation is proposed, defining three distinct states. The state of sand migration shifts when local blockages reach a threshold, transitioning from particle migration to block displacement.

The use of expandable screens simplifies completion proce-dures. Many operators perceive that screen performance de-pends on whether it is fully compliant with open hole; how-ever, it is impossible to guarantee total compliance. Evidence indicates that, in addition to filling the micro-annuli and plug-ging the screen, mobile fines and sand have the potential to create hot spots and erode the screen, thus creating sand-production problems. This paper presents laboratory results that illustrate the feasibility of applying a curable, low-viscosity composition to stabilize and strengthen unconsolidated formations. Over-displacement is not necessary in this process. The composition forms a tacky, ultra-thin film, creating bonds between grains that cure with time and temperature once coated onto the sur-faces of formation particulates. Unconsolidated formation sands, even those with high content of clay fines, were con-solidated with negligible loss of initial permeability. The results obtained from this study demonstrate the im-portance of stabilization of the formation. The screens, whether wire-wrapped, pre-packed, expandable, or simply slotted pipes, serve as a mechanical support to prevent col-lapse of the wellbore. A combination of treating unconsoli-dated formations with an ultra-thin, curable composition and installing a mechanical liner should provide an economical and reliable means for sand control. The use of such curable sand-stabilization treatments may therefore eliminate the per-ceived need for compliant expansion, placing a premium on the mechanical strength of the sand-control technique selected. Introduction Wellbore instability often results from a combination of me-chanical and chemical instability; however, mechanical factors play a dominant role in wellbore instability during the drilling phase of operations. Drilling a well in a formation changes the initial stress state and causes stress redistribution in the vicin-ity of the wellbore. The redistributed stress state may exceed the rock strength and cause failure.[1, 2] Once a wellbore or a perforation tunnel is introduced into a friable sand formation, a plastic zone develops and formation failure can follow. Production and cyclic loading are the main reasons a plastic failure zone expands into a formation. For-mations that are considered soft or poorly consolidated are often plagued by sand production. Formation sand production can result inplugged gravel packs,plugged sand screens,plugged tubulars, and potentially sand fill in the surface flow lines and surface equipment, as well aslost production.3–6 In addition to damage caused by plugging, sur-face equipment can be eroded because of abrasive, sand-laden fluid flowing from the well. In a worst-case scenario, sand-production problems can cause total well failure or the need for recompletion resulting from casing collapse, openhole col-lapse, or both. Conventional treatments for sand-producing wells include gravel packing, frac-packing, formation consolidation, and squeeze treatments using resin-coated sand slurries. These treatments control sand production and are based on gravel-packing technology that relies on the creation of stable bridges at the face of the formation to minimize damage to the pack. The filtering mechanism provided by the gravel pack is effec-tive for controlling sand production, but the permeability of the pack can decrease over time. This decreased permeability results from a continuous migration of formation fines toward the wellbore, which causes progressive plugging and results in high skin damage and reduced productivity. Sand-Control Screens The primary function of screens is to provide mechanical support to prevent proppant or gravel placed in the perforation tunnel and formation from flowing back into the wellbore. Keeping proppant in place will support the perforation tunnel and/or fracture thus maintaining a highly conductive flow path into the wellbore. In all gravel pack and frac-pack comple-tions, the gravel and proppant act as the primary filter to help prevent fines migration and sand production.

Sand-control methods were first used in water wells, and modified methods later were applied to oil and gas wells. The most recent application for sand control is in waste-disposal wells. The increasing use of unconsolidated sands as disposal zones has created a need for better sand-control systems. We suggest that the primary causes of sand-control problems in disposal wells are (1) greater completion intervals, (2) intermittent operation of the well, and (3) chemical characteristics of the injected effluent. Therefore, in order to prevent sand production in disposal wells, consideration must be given to (1) formation characteristics, (2) completion fluid, (3) type of completion, and (4) completion method. Two universally used methods of sand exclusion, with suggested modifications for disposal wells, are the method of in-place sand consolidation with plastics and the use of gravel packs in conjunction with sand screens. Sand consolidation has limited application because of the large completion intervals normally used in disposal wells and because of possible chemical reactions with injected effluent. However, a gravel-pack sand-screen completion generally eliminates the three primary causes of sand production in disposal wells. Factors of prime importance are (1) the drilling and completion fluids, (2) formation grain size and composition, (3) size and amount of gravel, (4) pumping rate, (5) pressure, and (6) gravel concentration. Field and laboratory data show that the method of gravel-pack sand-screen completions can be used successfully over intervals as great as 585 ft (178 m) in unconsolidated Frio sands.

Low-temperature oxidation (LTO) of crude oil has been employed to investigate its potential as a sand consolidation technique. Loose sand (20/30 mesh) saturated with crude oil (18 – 20 API) and brine was subjected to air injection at a low temperature (100 – 150 C) for a period of time (6 – 18 hours). The sand packs developed compressive strengths ranging between 375 and 1264 psi and suffered a maximum permeability loss of 22%. It was found that higher oxidation temperatures reduced the consolidation time and increased the compressive strength; but had no effect on the magnitude of permeability loss. Heavier oils required less oxidation time, caused slightly larger permeability losses, but had an insignificant effect on compressive strength. The presence of clay enhanced the LTO reactions by shortening the oxidation time and increasing the amount of residue deposited on the sand grains. This greatly increased the compressive strength, but at the expense of larger permeability losses. When interstitial water was present with clay, the permeability loss was increased further while the compressive strength was slightly reduced. Acid treatment had no effect on the residue deposited on the sand grains. Experimental testing as well as two predictive models showed that this technique provides sufficient compressive strength to withstand sand-free, high flow velocities and results in much smaller permeability losses compared with plastic consolidation. Introduction Sand production is considered to be one of the major operational problems in producing poorly consolidated reservoirs. Sand influx into the wellbore may lead to various problems such as erosion of valves and pipelines, plugging the production liner and sand accumulation in the separators. Cleaning and repair works related to sand production plus loss of revenue due to production rate restriction amount to great costs incurred by the industry every year. Furthermore, undetected erosion of production equipment may pose a major safety hazard in case of high-pressure gas wells. Therefore, sand control has attracted much research effort for more than six decades. Several methods are commonly used to prevent or reduce the flow of sand particles into the wellbore during the course of production. These methods use either mechanical means (sand screens, filters, perforated or slotted liners, gravel packing) or chemical agents (plastic consolidation). Certain completion and production practices are also employed to minimize or prevent sand production. Most existing sand control methods have their own drawbacks. In the mechanical methods, the setting of liners and gravel packing around liners may require a long time which adds to the cost. Moreover, the formation sand is still free to move and hence may plug the gravel pack or liner. In the chemical methods, some difficulties may arise in achieving polymerization of the injected resinous material in the formation - to consolidate sand particles - and still maintain adequate permeability. Furthermore, these resinous materials are proprietary and quite expensive. All these drawbacks leave a substantial and unfulfilled need for a sand control method capable of effectively preventing the flow of sand particles into the wellbore. Low-temperature oxidation of oil had been experimented with as a means of in-situ consolidation of sand. In this paper, the results of a new form of this process are presented. Low Temperature Oxidation Crude oils react with oxygen through numerous and complex reactions. These reactions have been found to fall into distinct categories depending on the reaction temperature. At temperatures below 500 F, the low temperature oxidation (LTO) reactions are dominant, and produce mainly oxyginated hydrocarbons such as alcohols, aldehydes, ketones, acids and hydro-peroxides with little carbon oxides. P. 547

Experimental investigation of factors affecting gravel pack efficiency for thermal recovery wells in Bohai Bay, China

Sand production is a common problem in wells completed in unconsolidated or poorly consolidated formation. Several problems are associated with sand production including erosion damage, and plugging of the well and surface production equipment, such as lines, valves, etc. Various mechanical solutions have been implemented to control or eliminate sand production. Screenless completion is an alternative method to conventional sand control techniques. Screenless completion methodology involves sand consolidation, a field-proven technique which offers viable and effective strategies to prevent sand production throughout the life of the well. Sand production can lead to production loss through sand filling up, production tubing restrictions, etc. Consequently, the need for an effective sand control is mandatory. Sand consolidation is a promising technique due to significant advancement in chemicals development for sand control. The challenge with the chemical consolidation systems is their ability to provide the highest possible compressive strength with minimum permeability reduction. A newly developed sand consolidation system was assessed in this study for its effectiveness in both sand consolidation and retained permeability. Two techniques were investigated in preparation/conditioning of sand samples. Following the conditioning state, the sand samples were treated with equivalent amounts of the two components of the newly developed sand consolidation system (Resin-A and Resin-B). A consolidation chamber was used to cure sand under simulated downhole conditions of a temperature (300°F) and a stress of 3,000 psi. The consolidated sand sample prepared using 3 wt% KCl brine preflush was associated with a reduction in plug permeability of more than 99% with a compressive strength of 1,100 psi. In the second method, which employed a diesel preflush in the sand sample preparation step, an average permeability of 63 mD and unconfined compressive strength nearly 900 psi were obtained. The effect of temperature and flow rate on return permeability were investigate. The paper presents in detail the lab work conducted to evaluate/optimize a newly developed chemical system for sand consolidation in HT/HP gas wells.

The Baram and Alab fields located in offshore Sarawak and Sabah, Malaysia, are composed of highly unconsolidated and friable sandstone reservoirs having multiple pay zones. The primary objective of the application of ESS® was to combat sand control problems while reducing well costs and simplifying operations by replacing gravel packing. The secondary objective of the ESS® application was to maximize productivity by eliminating / reducing skin damage which is inherently associated with gravel packing. Additionally, ESS® maximizes the wellbore radius by the expansion of the screen, facilitating the process of future well interventions and the application of "intelligent" well completions. Three wells in the Baram field were completed using ESS® with mixed success. The lessons learned from the Baram field were later utilized to optimize the methodology of application of ESS® in the two subsequent wells in Alab field. Experiences gathered by other operating companies e.g. Shell Brunei, Shell Expro and BP in the North Sea were also taken into consideration as a step forward in the learning curve to ensure successful installation in the Alab field. Further testing results performed by the vendor were also incorporated in the design and operational aspects of the wells. Consequently, ESS® has been successfully installed and overall objectives were achieved in the Alab field. Since the ESS® hardware was manufactured and installed by a single vendor, the exchange of data and information between various companies was easy to obtain. Study and research findings from the facilities of Shell and the vendor in Aberdeen and Houston were also incorporated in the design aspects of the wells that were completed in the Alab field. Due to the presence of pressure differential between the zones and contrasting reservoir fluid and rock characteristics it was necessary to produce the wells selectively with annular zonal isolation. Attempts to isolate the pay zones in the first well (BA-102) using Expandable Isolation Sleeve (EIS®) were not successful. However, modifications in the design for the subsequent wells (substitution of EIS® by EXP packers) yielded much better results and achieved well objectives. The primary objective of the ESS® application, i.e. sand control, was successfully achieved, based on the analysis of surface fluid samples. The wells are flowing at the expected rates. Sufficient well test / production data is not available on hand to assess the effectiveness of the ESS® in terms of impairment / improvement of productivity. Pressure build up (PBU) tests are planned in order to determine the extent of skin damage caused by the ESS®. Shell Brunei experienced satisfactory productivity index (P.I.) after completing their wells in S.W. Ampa and Champion fields, offshore Brunei1. Innovations and modifications of the existing equipment and methodology of application of ESS® technology are also proposed. These modifications generate cost savings and simplified deployment for the operator.

Gravel packing can be successfully performed on high-angle wells (70°-80°) when special consideration is given to the completion design and details of field procedures and practices. Through analysis and modification of current techniques and research done on full scale models, Chevron experimented with and developed several techniques to successfully gravel pack high-angle wells . The high-angle gravel packs were performed utilizing the following criteria: solids free completion fluids, low-side perforating, modified screens, combination tools (circulating pack), maximum tailpipe (washpipe)-liner ratios, medium viscosity carrier fluids, maximum pumping rates, and special attention to quality control. Sand-out pressures, subsequent pack tests, quantity of gravel placed (percent packed volume) and extended flow tests of up to 20 MMCFD have proven the success of the design and procedures implemented.

Hydrocarbon production from unconsolidated sand reservoirs requires sand control usually consisting of the installation of a screen combined with gravelpacking. Several existing criteria such as Tiffin, Saucier and Coberly can be used for optimal selection of the sand control design. Sand and fines production in oil and gas wells are one of the main challenges and can result in failures of production systems. Especially in unconsolidated sand reservoirs, proper sand control practices are required to prevent reservoir sand production. At Staatsolie sizing of sand control design is based on the Saucier method incorporating the results of reservoir sand particle size distribution of side wall core samples.A Staatsolie-Suriname in-depth research of sand control practices in shallow, low-pressure, heavy-oil unconsolidated sand reservoirs completed with progressive cavity pumps will be presented. The conventional sand control method applied is the installation of formation sand sized wire wrapped screens and gravelpack completion on uniform and non-uniform distributed reservoir sands. Stand alone screen completions have revealed its application in uniform distributed reservoir sands. Sand production and control on depleted and complex reservoirs based on the conventional method has become a major challenge. In Suriname, in three onshore fields approximately 1,500 wells are completed and are in production. With improved sand control practices, failures have been reduced to less than 5 wells per year.The study has demonstrated the challenges and benefits of sand control in these complex unconsolidated Tertiary reservoirs. This has resulted into increased production and economic benefits. Results of lab tests and field cases will be presented and recommendations will be given on the best approach for sand control practices and the most cost effective sand control solutions in unconsolidated shallow sand reservoirs.

Sand production presents numerous technical, economic, and environmental challenges to the oil and gas industry. Sand particles may erode production equipment, resulting in increased maintenance costs and potential equipment breakdown. In addition, the influx of sand into the wellbore can lead to reduced production rates, reduced efficiency of reservoir sweep, and ultimately, reduced recovery of hydrocarbons. Also, sand production impacts project profitability because of the cost of sand control measures and potential lost production. There are two broad classes of methods used to control sand in oil reservoirs: mechanical methods are designed to physically restrict sand particles from entering the wellbore, while chemical methods involve the modification of reservoir properties to increase sand consolidation or fluid mobility. Chemical consolidation uses chemicals (resin, polymer gels, foams, nanoparticles, bacteria, etc.) to bind sand particles together to create a stable formation. For optimal sand control, combined approaches use a combination of mechanical and chemical methods. Sand management is an important part of oil and gas production, and several new technologies such as artificial intelligence and machine learning, autonomous sand monitoring systems, sand control measures, chemical sand control technologies, multilateral sand screens, advanced sand screen materials have been developed to improve sand management in the industry. Current developments and strategies in chemical consolidation techniques, sand management, control and prevention techniques are reviewed in this paper. Keywords: sand production; chemical consolidation; resin; polymer gels; foams; machine learning; artificial intelligence; sand monitoring systems.

Sand production has historically been a problem associated with some consolidated, poorly consolidated, and unconsolidated sand formations. The result is usually lost production due to formation sand and fines plugging gravel packs, screens, perforations, tubular, and surface flow lines or separators. Completion methods applied to minimize sand production include: gravel packing, sand consolidation, critical production rate, oriented/selective perforation, FracPacking, or any combination of these methods. These techniques are used in consolidated, poorly consolidated, and unconsolidated sand formations. However, there are no guidelines available in the literature on how these methods are selected. Mechanisms for sand failure include: tensile, shear, cohesive, and pore collapse. Additionally, failure due to chemical effects can occur when the cementation materials are weakened due to chemical interactions. Many mathematical models have been presented in the literature to predict sand failure, and consequently determine sand production. These models are based on different failure mechanisms and include: pressure drawdown/compressive strength, failure based on a given failure criterion such as Mohr Coulomb, cohesive strength failure, elastoplastic failure around a perforation, viscoplastic modeling, and empirical correlations. However, there are no guidelines on how these models are applied based on the characteristics of the sand formation. Experimental studies have been presented in the literature to model sand failure. These studies include sand arching, hollow cylinder strength, triaxial and hydrostatic, and large scale testing. Laboratory testing are designed to study a given failure mechanism, and thus to predict sand production. The objective of this paper is to categorize sand formations that potentially exhibit sand failure and sand production. Based on this characterization, an appropriate laboratory testing and mathematical modeling are recommended, and a completion method is suggested. Examples from standstone reservoirs in Saudi Arabia will be used to demonstrate certain methods used for sand control.