Cement Placement Research Articles

The Use of Antibiotic-Impregnated Cement for Infection or Mechanical Support in Diabetic Foot Osteomyelitis A Systematic Review and Meta-Analysis

Background Diabetic foot infections are difficult to eradicate and could lead to serious complications such as multiple surgeries, amputation and mortality. Culture-based IV antibiotics and particularly amputation are usually the available options. Only few studies articles reported the use of cement impregnated with antibiotics to fill temporarily or permanently a bone defect, but with no evidence synthesis yet. Therefore, this study aims at assessing the outcomes of the use of antibiotic-impregnated cement for infection or mechanical support in diabetic foot osteomyelitis. Methods A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. We searched multiple electronic databases using the terms “osteomyelitis AND cement AND diabetic AND foot.” The quality of the included studies was evaluated using the Joanna Briggs Institute Appraisal Tool. Results Six studies met the inclusion criteria combining 82 patients with 85 procedures. With a mean follow-up period of 22 ±14.6 months, the meta-analytical results were as follows: (1) the weighted healing rate was 85.2%, (2) 63.6% of cement were kept in place, (3) 8.2% of cement had to be exchanged, (4) 24.4% of placed cement had to be removed, (5) minor amputation following cement placement was 13.4%, and (6) the rate of secondary surgery was 18.7%, with arthrodesis being the most common (94%). Conclusion There are limited studies available detailing the outcomes of cement use in diabetic foot osteomyelitis. In the case of the difficult-to-heal osteomyelitis of the diabetic foot and whenever a peripheral bone rim could be preserved, filling the void within to deliver local infection control and to assure mechanical resistance for ambulation could be a non-radical limb preserving option. Level of Evidence Level IV

A Review of the Effect of Mechanical Vibrations on Bone Cement and Implants during Implantation in the Bone Cavity

This study of the literature looks at how mechanical vibrations affect the placement of implants and bone cement into bone cavities. The study investigates the many consequences of vibrations, from vibrational injury to potential advantages like enhanced osseointegration. Studies on the use of nanoparticles in bone cement to improve its mechanical characteristics and antibacterial resistance are presented, among other study findings. The paper also discusses the creation of innovative biomaterials that have better mechanical strength, anti-washout qualities, and biocompatibility, such composite bone cements and nanohybrids. The complicated interactions between mechanical vibrations, biomaterials, and orthopedic surgery are highlighted in this review of the literature, which also offers suggestions for improving implant stability and patient outcomes.

Feasibility biomechanical study of injectable Biphasic Calcium Phosphate bone cement augmentation of the proximal femoral nail antirotation (PFNA) for the treatment of two intertrochanteric fractures using cadaveric femur

This study evaluated the feasibility of the femoral bone after fixation using biphasic calcium phosphate cement-augmentation of the proximal femoral nail antirotation (PFNA) compared with PFNA without cement. This study presented to compare the stiffness, fatigue testing, and compressive strength between stable (AO31-A2.1) and unstable (AO31-A3.3) intertrochanteric fractures treated by cement augmented PFNA of the cadaveric femoral. Biphasic calcium phosphate cement was injected to align and compatible with PFNA and the reconstructive procedure was monitored the cement placement using x-ray imaging during operation. The testing demonstrated that the cement could be injected through a small needle (13 G, 16 cm length, 1.8 mm inner diameter) within a suitable operating time. The feasibility study of the biomechanical testing was divided into three tests: stiffness test, fatigue cyclic load, and compression test. The results showed that the cement-augmented specimens exhibited higher stiffness than the control specimens without cement. The cement-augmented specimens also showed lower strain energy during the fatigue test, resulting in higher compressive strength (4730.7 N) compared to the control specimens (3857.4 N). There is a correlation between BMD and fracture load and the increase in compression load of the cement-augmented femoral compared to the controls as well as an increase in strain energy of fatigue cyclic testing was found. Biphasic calcium phosphate cement-augmented of the PFNA biomechanically enhanced the cut-out resistance in intertrochanteric fracture. This procedure is especially efficient for unstable intertrochanteric fracture suggesting the potential benefits of using biphasic calcium phosphate cement in medical applications.

Biomechanical evaluation of screw and cement placement strategies for treating medial uncontained tibial defects in total knee arthroplasty: A finite element analysis.

Total knee arthroplasty faces challenges in the management of medial uncontained tibial defects, affecting prosthesis stability and implant survival. The use of screws and bone cement is a preferred approach; however, optimal screw insertion techniques lack consensus in the existing literature. The present study aimed to address this gap by exploring optimal screw and cement placement strategies, focusing on their biomechanical implications. The present study conducted a finite element analysis using a knee prosthesis model with a defined uncontained tibial defect. Various parameters were systematically adjusted, including the number of screws (1, 2 or 3 screws), screw lengths (10, 18, 30 or 40 mm), lateral-medial screw positions (2, 4 or 6 mm laterally) and abduction rotation angles (0, 5, 10 or 15 degrees). These adjustments were made to evaluate their specific and combined impacts on the vertical displacement and abduction angles of the tibial tray. The results revealed that incorporating three-screw reinforcement markedly reduced vertical displacement, while the single screw in the middle position exhibited superior performance in preventing the deformation of abduction angles compared to scenarios with two screws at anterior and posterior positions without a middle screw. Longer screws and smaller abduction angles contributed to decreased movement of the tibial component. Furthermore, the lateral adjustment of the screw position led to an increase in vertical displacement values, reaching ~1.5% when shifted 6 mm laterally. On the whole, the finite element analysis in the present study suggests that, for the treatment of medial uncontained tibial defects, three-screw reinforcement is advantageous for larger defects. Longer screws and a smaller abduction angle are deemed favorable. Moreover, the results underscore the superiority of medial screw placement over lateral placement. It is imperative to note that further clinical validation is essential to corroborate the biomechanical implications observed herein.

A Systematic Review on Outcomes of Vertebroplasty and/or Balloon Kyphoplasty for Osteoporotic Vertebral Compression Fractures

With nearly 50% of all osteoporotic fractures, osteoporotic vertebral fractures are the most frequent consequence of osteoporosis. Vertebroplasty (VP) and balloon kyphoplasty (KP) are two distinct techniques that have been introduced for the therapy of symptomatic fractures without neurological disorders. The results for osteoporotic vertebral compression fractures (VCFs) from VP and/or balloon KP will be the focus of this study. An extended search was done in databases of PubMed, MEDLINE, Wiley library, and Google Scholar between 2001 and 2020. In this systematic review, 16 studies were cited. Studies, in which the outcomes for osteoporotic VCFs from VP and/or balloon KP were noted, were included in the study. These findings demonstrated that for the treatment of osteoporotic (VCFs, VP, and KP) appeared to be complementary procedures with particular indications and demonstrated similar good clinical outcomes. Balloon KP and VP are effective and beneficial methods for treating VCFs, with balloon KP being slightly more effective for osteoporotic fractures due to its advantages in minimizing fractures, controlled cement placement, deformity relief, and immediate pain relief.

Evaluation of the efficacy of the Lentulo spiral filler operated at four different speeds and with two different techniques in cadaveric canine teeth of dogs.

This study evaluated the effect of filling technique and rotational speed on the efficacy of sealer cement placement using the Lentulo spiral filler. Cadaveric maxillary and mandibular canine teeth (n = 74) from age and breed matched fresh-frozen adult canine cadaver heads were utilized. Following routine mechano-chemical preparation, teeth were randomly divided into 8 treatment groups with varying rotational speeds [250-2,000 revolutions per minute (RPM)] and fill techniques (backfill technique versus pumping technique). The quality of the sealer cement fill was evaluated radiographically before and after master gutta percha cone placement. Percentage of voids present in the apical, midbody, and coronal portions of the tooth were subjectively scored as: no voids present, voids present in less than 25% of the area, voids present in 25-50% of the area, voids present in greater than 50% of the area. The apex was also scored as underfilled, adequately filled, or overfilled. Operating the Lentulo spiral filler at 2,000 RPM resulted in the best quality fill regardless of filling technique. The pumping technique with placement of the master gutta percha cone had a higher probability of success as compared to the backfill technique, but this finding lacked significance. Regardless of speed or technique, the apical region had the highest quality of fill. The addition of the master gutta percha cone improved the quality of fill. Therefore, we recommend using the Lentulo spiral filler at higher speeds with a pumping technique (followed by addition of a master gutta percha cone) to improve the quality of epoxy resin-based sealer cement placement.

Calcaneoplasty with radiofrequency cementing following balloon reduction

The standard surgical procedure for complex calcaneal fractures is open reduction, internal reduction and internal stable angle plate osteosynthesis via alateral approach. More recently, options for minimally invasive and percutaneous surgical strategies have been presented [4, 7]. As a possible procedural alternative for acovered, surgical treatment of calcaneal fractures, calcaneoplasty is discussed and applied in this context [5]. In this case series of five complex calcaneal fractures presented here, aballoon catheter was used for percutaneous reduction to restore the alignment of the calcaneus.This was followed by placement of PMMA cement in radiofrequency application and osteosynthesis using percutaneous cannulated screws. This Vicenti technique allows stable reduction and retention with early partial weight bearing with an overall low complication rate [17].

Limb Salvage in Diabetic Patients With Combination of Radical Excision, Antibiotic Impregnated Bone Cement, and External Fixator Application

In patients with diabetes, foot ulceration is a major cause of morbidity and hospitalization. The combination of deep ulcers and underlying osteomyelitis in patients with diabetes frequently leads to chronic nonhealing foot ulcers. These patients have often ended up with amputation. From 2003 to 2017, 17 of 175 diabetic patients (11 males and 6 females, 37 to 82 y old) were treated for diabetic foot and presented with complaints of ulceration, osteomyelitis, and foot gangrene. Magnetic resonance imaging–guided necrotic tissue debridement was performed, after the placement of antibiotic-impregnated bone cement, and soft tissue defect reduction was performed with an external fixator. Approximately 4 weeks later, polymethylmethacrylate was removed, and then the external fixator was removed after the soft tissue defect was closed. No patients had recurrent ulceration or osteomyelitis seen on radiographs up to their latest follow-up. There was pin tract infection in 2 patients who were treated with oral antibiotics and wound dressings. All patients have a fibrous union in the metatarsophalangeal joint. Compared with other radical techniques such as amputation, amputation, and long-term wound dressings, salvage of limbs with an external fixation can be used in selected patients who have osteomyelitis and soft tissue defects after debridement. Level of Evidence: Diagnostic level III—nonrandomized controlled cohort study.

Cement Placement Modeling—A Review

SummaryEnsuring cement sheath placement is of paramount importance for the success of a primary cementing operation. Poor mud displacement and fluid contamination can lead to cement isolation failure, loss of production, and even well abandonment. Over time, many cement placement computerized models have been developed, leading to a significant number of theoretical and case history papers. However, using these to design a cement job is difficult because their physical and mathematical assumptions are most of the time unclear, and because their application requires balancing precision with computation time. Models that are too precise may lead to very long runs, while oversimplified models could result in nonpredictive simulations. To the authors’ knowledge, nothing has been published to explain how to perform efficient predictions with a cement placement computerized model. Such is the object of this paper. It presents an extensive analysis of all the available cement placement computerized models, highlighting their advantages and disadvantages and listing their assumptions. This analysis indicates that (1) the actual methods used to estimate the equivalent circulating density window are not rigorous enough; (2) there still exist a lot of uncertainties when predicting the tubular standoff; (3) modeling fluid contamination, especially when the fluids are not compatible, remains very cumbersome, if not impossible, because the true interfaces’ physics is not completely considered; (4) a local contamination observed at an intermediate time can disappear at the end of the simulation due to numerical diffusion, meaning that just looking at the concentration maps at the end of placement is not sufficient to judge the efficiency of a displacement scenario; and (5) changes in geometries along the cement sheath are not considered with precision. This work allows establishing guidelines to help understanding how to manage simulation inputs and analyzing and communicating the produced results.

Unconventional Bradenhead Cementing in the Delaware Basin Case History

SummaryThis Delaware Basin case history describes a bradenhead cementing method that improves zonal isolation and top of cement (TOC). Common solutions for cementing depleted formations include stage tools, low-density slurries, and reverse circulation. For this bradenhead method, cement is pumped through the wellhead valves and down the annulus to a target loss zone. Field data, laboratory data, and the engineering model support the improvement bradenhead cementing provided across depleted formations.The depleted Brushy Canyon Formation serves as an injection interval for a two-stage bradenhead cement job. This approach isolates formations below the Brushy Canyon with a conventional first stage, while achieving TOC with the second stage pumped down the annulus. Fracture gradients of the injection interval and casing shoe constrain the cement design. To achieve adequate cement placement, the design phase includes the pressure calculations required to start flow and injection for the bradenhead stage. Reactive spacers are utilized to prevent annulus fluid level drop in extreme cases. A benchmarked cement bond log (CBL) quantifies the results and validates this unconventional cementing method.More than 50 two-stage bradenhead cement jobs were executed with a TOC success rate of 100% in intermediate and production hole applications. CBL data obtained after cementing the intermediate casing confirm the two-stage bradenhead as a placement method. In areas constrained by casing shoe pressures, CBL data identified potential areas of shallow injection. These data resulted in a modification of the fluids pumped. Use of these re-engineered fluids reduced injection initiation pressures and improved cement bonding across salt and anhydrite formations. Cementing costs were reduced by eliminating stage tools, annular casing packers, and low-density cement slurries. Pumping the bradenhead job offline (off the rig’s critical path) reduces cost further. These features support bradenhead cementing as an effective solution for wellbore sections with a potential injection zone.The regulatory requirement to place cement above depleted formations resulted in many innovative cementing methods. Stage tools, low-density slurries, and reverse circulation are attempts to avoid formation breakdown, but these methods increase cost and have limited reliability and integrity. Bradenhead cementing takes advantage of the depleted interval to aid in cement placement. Although counterintuitive, bradenhead cementing has proved to be a cost-effective solution that improves zonal isolation and eliminates integrity risks associated with stage tool failures.

Cement logs evaluation Ghadames Basin, (Al Wafa Gas field), case study, Libya

The acoustic logging method is the most commonly used to qualify a cement job. It can be run several hours or several days after the cement placement and evaluates the quality of the bond (acoustic coupling) between the casing, the cement and the formation. It measures the attenuation of the sound signal as it propagates through the casing, cement and formation and returns to the sensor. This technique and will help spot free pipe, partially bonded or fully bonded pipe. The aim of this paper is analyses and evaluates cement logs data in two wells within Al Wafa Gas field, the cement logs analysis results of two wells shown variables cement condition behind the casing. The well A24-NC169A, analysis showing a good cement condition for both casing and formation as the signature of cement logs showing very low amplitude reading due to high attenuation of waves in cement bound log because the cement was good behind casing. The well A56-NC169A, showing variable results, as good cement condition behind the casing bond to casing, formation, micro- annual and channeling condition. The gamma- ray ranging from 40 to 150, as sand to shaly sand sediments, transit-time was normal, cement bound log recorded variables from low, medium to high amplitude (18 to 56) due to different wave attenuated depending on cement condition (good to partially cement). Variable density log showing variable results (Formation arrive, casing arrive, no casing arrive and no formation arrive, all depending on cement behind the casing. In general, the results revealed good cement condition.

Effects of Material Thickness and Pretreatment on the Interfacial Gap of Translucent Zirconia Restorations with Self-adhesive Resin Cement.

The first objective was to determine if the dual-curing of self-adhesive resin cement (SAC) with reduced light penetrating through zirconia had an effect on interfacial gap of zirconia restorations. The second purpose was to examine whether pretreatment methods for universal adhesive affected interfacial gap. The last aim was to compare the microhardness of SAC polymerized under different zirconia thicknesses. This study evaluated self-adhesive resin cement (RelyX U200, 3M ESPE) after different pretreatment with universal adhesive (Single Bond Universal, 3M ESPE) under different polymerization conditions. CAD/CAM inlay cavities were prepared on extracted third molars. Translucent zirconia restorations were milled using Katana UTML (Kuraray). The teeth were divided into three groups: Groups I, II, and III in which the restoration thicknesses were 1, 2, and 3 mm. Each Group had three subgroups according to different pretreatment methods. For subgroup-1, no pretreatment was done on the prepared cavity. For subgroup-2, universal adhesive was applied and light-cured before cement placement (precure method). For subgroup-3, universal adhesive was applied; however, light-curing was done after cement placement (cocure method). After thermo-cycling, the interfacial gap at the restoration-tooth interface was investigated using swept-source optical coherence tomography imaging. Finally, microhardness was measured for SAC under different zirconia thicknesses. For statistical analysis, the interfacial gap was analyzed using two-way analysis of variance (ANOVA) to test the effect of cavity depth and pretreatment. In terms of each cavity depth and pretreatment, the interfacial gap was compared using one-way ANOVA and Scheffe's test. One-way ANOVA was also performed for comparison of the Vickers hardness results. Different thicknesses of the restoration resulted in differences in interfacial gaps except between the precure method of Groups I and II (p<0.05). The effect of universal adhesive pretreatment was different depending on the restoration thickness with exceptions in Groups I and III (p<0.05). Vickers hardness number decreased as the low radiant exposure of light was applied (p<0.05). Interfacial gap of zirconia restorations can differ depending on the material thickness, pretreatment, and activation mode. Reduced light intensity penetrating through zirconia may lead to higher interfacial gap percentage and lower microhardness of the self-adhesive resin cement. Application of a universal adhesive showed similar or reduced interfacial gaps in the cement space.

Risk factors for bone cement displacement after percutaneous vertebral augmentation for osteoporotic vertebral compression fractures.

PurposeTo explore the risk factors of bone cement displacement after percutaneous vertebral augmentation (PVA) in patients with osteoporotic vertebral compression fracture (OVCF).MethodsWe retrospectively reviewed the records of 1,538 patients with OVCF treated with percutaneous vertebroplasty (PVP) or percutaneous vertebroplasty (PKP) from January 2016 to June 2021. Patients were divided into bone cement displacement group (n = 78) and bone cement non-displacement group (n = 1,460) according to the radiographic images. Possible risk factors for bone cement displacement were noted, including age, gender, body mass index (BMI), bone mineral density (BMD), underlying disease, number of fractured vertebrae, involved vertebral segment, surgical method, surgical approach, vertebral height, Cobb angle, cement leakage, the viscosity of bone cement, bone cement diffuse ratio, degree of bone cement interweaving, sagittal bone cement placement, targeted location of bone cement, the distance between the bone cement and the upper and lower endplates, the time of wearing brace and postoperative osteoporosis treatment. Risk factors were identified with univariate and multivariate logistic regressions and the discrimination ability of the predictive indicators was evaluated using area under the curve (AUC) of the receiver operating characteristic (ROC).ResultsIn multivariate regression, independent risk factors for bone cement displacement included: high restoration of Cobb angle (OR = 2.019, 95%[CI] 1.545–4.852, P < 0.001), cement leakage (anterior edge) (OR = 1.727, 95%[CI] 1.05–2.20, P < 0.001), small degree of bone cement interweaving (OR = 1.917, 95%[CI] 1.129–2.747, P < 0.001), non-targeted location of bone cement (OR = 2.323, 95%[CI] 1.645–4.134, P < 0.001), short duration of brace wearing (OR = 3.207, 95%[CI] 2.036–4.348, P < 0.001) and postoperative osteoporosis treatment (OR = 0.422, 95% CI = 0.323–0.547, P < 0.001). The AUCs for the high restoration of Cobb angle, cement leakage (anterior edge), small degree of bone cement interweaving, non-targeted location of bone cement, short duration of brace wearing and non-postoperative osteoporosis treatment were 0.784 (95% CI, 0.747–0.821), 0.811 (95% CI 0.764–0.859), 0.917 (95%CI 0.864–0.970), 0.610 (95%CI 0.552–0.669), 0.854 (95%CI 0.816–0.892) and 0.756 (95% CI, 0.712–0.800), respectively.ConclusionHigh restoration of Cobb angle, cement leakage (anterior edge), small degree of bone cement interweaving, non-targeted location of bone cement, short duration of brace wearing and non-postoperative osteoporosis treatment were the independent risk factors of bone cement displacement after PVA.

Evaluation of common cementing practices affecting primary cementing quality

The quality of cement placement in primary cementing depends on many facets of the cementing procedure. In this paper, we simulate the fluid displacement process of a typical horizontal well in Northern British Columbia. We analyze how variations in some of the common cementing practices may improve the displacement efficiency. By using excess cement volume, the residual mud can be gradually removed as long as there is a sufficient pressure gradient to yield the mud. Increasing the centralizer usage is demonstrably effective in removing residual mud in the deviated section, and the eccentricity is significantly improved. Performing staged cement allows improvement in displacement by allowing flexibility in frictional pressure loss management (often crucial in long horizontal wells). Targeting different strategies for vertical and deviated sections results in improved efficiencies. • Excess cement volume leads to better displacement efficiency. • Poor cementing quality identified through combination of CBL and simulation. • Increased centralization works, as we know! • Staged cementing allows reduced frictional pressures and focus on vertical and deviated sections separately. • Increased density difference in the vertical is effective; slow flow and slumping improves the horizontal.

Revisiting the Microleakage in Tooth-coloured Sandwich Restorations

The placement of glass ionomer cement as lining material below composite fillings was introduced by McLean and Wilson in 1977. This technique incorporated different layers of restorative materials placed onto tooth, similar to layers of a sandwich. It was proposed this technique will provide a molecular seal to dentine in addition to mechanical and aesthetic properties of composite resin. Placement of liner or an intermediate layer underneath the main bulk of restorative materials reduces polymerization shrinkage stress and resultant microleakage of the final restoration. To date, dentine adhesion and polymerization shrinkage are limitations of resin-based restorative materials. At present, wide array of tooth-coloured restorative materials with different formulations is available. Despite advancements in restorative dentistry, no single technique or material is ideal in both clinical effectiveness and simplicity. Clinicians may find themselves in a dilemma when choosing restorative materials and techniques that provide the best clinical results with minimal technique sensitivity or chairside time. The aim of this review is to present existing scientific evidence in microleakage and sandwich technique in restorations, and to discuss multiple approaches in sandwich restorations in effort to reduce microleakage of dental restorations. Clinical recommendations will be given based on evidence from multiple studies.

Nanosilica functionalized to switch from dormant to active for gas migration mitigation in Portland cement

AbstractWe describe the development of a nanosilica‐based oil and gas well cement additive which reduces the risk of casing‐casing annulus (CCA) and sustained casing pressure (SCP) through gas migration mitigation. Nanosilicas added to oil and gas well cement have been shown to accelerate cement hydration and reduce the cement porosity and permeability. While these qualities can potentially reduce the risk of zonal isolation loss, there are known rheological effects associated with adding nanosilicas to cements. It is known that cements loaded with nanosilicas produce gels prematurely, which has the deleterious effect of leading to air entrainment in cement and can also effect the pumpability of the cement slurry. This property can also interfere with gas migration mitigation because it is the formation of the gel that reduces the hydrostatic pressure on the formation. This can, in‐turn, allow for fluid from the formation to invade the cement prior to building enough mechanical strength to resist the fluid influx. The nanosilica product described in this article has been developed to display no gelation effect in the cement and a rapid hydration onset. These performance attributes are due to a specialized functionalization or coating on the nanosilica particle. At temperatures equal to or below 120°F (49°C), this functionalization renders the nanosilica inert from the cement until its timed degradation and thus does not interact with the cement phases responsible for the gelation behaviour observed with other commercially available nanosilicas in the process of cement placement.

\u2018Level-off\u2019 cement plugging method to cure lost circulation verified with case studies

Controlling lost circulation during drilling operations in a reservoir prone to fluid losses is typically remedied by cement squeezing or plug setting as the last resort. The aim being to minimize or stop drilling fluid losses and to regain full returns at surface, and to maintain wellbore integrity. Different placement methods of cement plugs have been discussed in detail in the literature, except for the ‘level-off’ method, which can be effective for curing complete loss circulation cases. Following modeling and calculations of this cement plug placement method, its design and execution procedures are discussed, together with two successful field cases in highly fractured carbonate reservoirs in the Middle East. Using drill pipe and a Retrievable-Test-Treat-Squeeze (RTTS) packer, set with some spacing from the loss zone, the method entails that the cement slurry is allowed to drop by gravity in order to cure lost circulation. As the column of fluid, mud and slurry in the well exceeds formation pore pressure, i.e., overbalanced conditions, a volume of acid-soluble cement slurry is allowed to slowly drop and freely penetrate the formation, i.e., through its fractures or caverns. During the penetration of this viscous slurry into the loss zone, the cement slurry can set and the fracture or fissure openings are plugged. Presented are detailed design calculations for the level-off placement technique, determination of required cement slurry and displacement volumes, and recommended displacement and RTTS packer setting depths. The expected depth of the top of cement plug is estimated. The design parameters are compared with field cases and explanations are given for possible discrepancies. Success of the operation is discussed in terms of final mud loss after cement plugging and Non-Productive Time mitigation. Detailed field procedures and execution are also presented. The level-off job is already practiced by the industry, but it is not published in the literature, in some cases they have different methods with causing some errors. To the best of authors’ knowledge, this is the first detailed description and stepwise calculation of the level-off cement placement technique in the literature.

脊椎固定術術後感染に対しバンコマイシン含有セメント留置術後に薬剤性過敏症症候群（DIHS）を発症した1例

脊椎固定術術後感染に対しバンコマイシン含有セメント留置術後に薬剤性過敏症症候群（DIHS）を発症した1例

Design and construction of an electrical furnace chamber based on RERIH system for high temperature

One of the important parts of an electric furnace is the combustion chamber which is used to heat or melt materials. The chamber system which is based on the refractory, element, Rockwool, insulator, and Hebel (RERIH) has been successfully designed to reach high temperatures up to 1200°C. The refractory layer is designed from a mixture of trimortar cement and water. To obtain one side of the refractory, the composition of trimortar cement used is 2 kg mixed with 1 liter of water. The number of refractory sides needed for the electric furnace chamber is six sides, each of which is placed on the front, back, top, bottom, left side, and right side. To retain heat in the chamber, the refractory is covered with heat-resistant ceramic fibers (Rockwool). The Rockwool used has a density of 160 Kg / m3 and a thermal conductivity of 0.23 W / m.K. The maximum temperature that this Rockwool can withstand is 1260°C. The third layer as a heat barrier in the chamber is an insulator, which is a lightweight brick block made of a mixture of alumina. This refractory thermal insulation brick contains more than 48% alumina oxide so it has lower thermal conductivity and better heat insulation qualities. Meanwhile, the last layer is the placement of Hebel or light cement blocks made from lime which is usually used for building walls. This Hebel has dimensions (w x w x h) of 600 x 200 x 100 mm3.

Monitoring of a reverse cement job in a high-temperature geothermal environment

Cementing operations in wellbores, especially for long casings, are often challenging and prone to deficiencies when not properly planned and executed. While exploring for and exploiting of geothermal resources at temperatures above the critical point of water was attempted in different drilling projects in recent years, the well design, and especially the procedure to run and cement long production casings became a key challenge for drilling engineers. For the first time, a reverse cementing job for a 2.97 km long production casing in a high-temperature geothermal well could be monitored and analyzed using a combination of permanently installed distributed fiber optic and electronic sensors as well as conventional well logging equipment. Data from the permanently installed sensors were used to monitor and evaluate the cementation process as well as the onset of the cement hydration. Based on the data, the understanding of downhole fluid dynamics during cementation could be improved. Our analysis suggests that the cement was diluted during cement placement and partly lost into the formation. These findings can help to better prepare for future drilling ventures under similar downhole conditions.