In order to obtain materials for improved printed circuit boards (PCBs) with high thermal conductivity and low dielectric losses, hexagonal boron nitride (h-BN) was incorporated into a polytetrafluoroethylene (PTFE) matrix. The filler loading in the composite was varied up to a filler volume content of 50%. Thermal conductivity and coefficient of thermal expansion (CTE) were investigated with respect to filler orientation. Further dielectric and mechanical properties were investigated. The incorporation of h-BN improved the heat transport significantly, while the loss factor decreased. Fillers with a higher aspect ratio have a greater effect on increasing thermal conductivity. For a filler volume loading of 30%, the in-plane thermal conductivity was up to 14 times higher than the thermal conductivity of the matrix, while the loss factor decreased slightly. The permittivity increased with the increasing filler volume content, while the CTE also decreased. Though the filler affects the mechanical properties negatively, 40% of the tensile strength could be maintained if a filler volume content of 30% is not exceeded. Such compositions may be used as raw materials for future printed circuit boards.

Formation sand production is one of the major production challenges in most of the mature fields in Malaysia. Often, failure in primary sand control equipment requires the operators to adopt through-tubing sand screens as remedial sand control. Due to the erosion prone nature of the thru-tubing metallic sand screen, operators are forced to impose limitation on the production rate coupled with stringent surface sand monitoring system to avoid surface flow line leakage and loss of primary pressure containment. Therefore, to seek a more robust technology than conventional metallic screens, alternative technology with through-tubing ceramic sand screen (TTCSS) has been considered with the idea of higher durability and resistance against erosion. This paper will discuss the performance and lessons learnt from the application of through-tubing ceramic sand screen throughout several mature fields in Offshore East Malaysia. Over the past two years, there have been about twenty-five TTCSS installations in Offshore East Malaysia. Seven pre-mature failure cases were observed, where sands were produced to the surface and even caused leaks on the flow line. The average effective production period for all TTCSS across all the fields ranges from 6 to 11 months. Teardown investigations have been conducted to diagnose the failure root cause. Most failed TTCSS exhibited similar failure patterns at the end caps, which house the spring compensator. Failure to stop the flow through the end caps led to substantial erosion at spring compensator and base pipe, inducing large flow path for sand production to the surface. Other than the design failure, application failure was observed at the ceramic rings due to their brittleness. Computational fluid dynamic simulation and laboratory testing have been conducted at the higher incremental production rates to support the observations from teardown inspections, refine the hypothesis of failure mechanism and enable an incremental design change to be modified into TTCSS. In order for TTCSS to be one of the competent candidates for remedial sand control, new improved standard design of TTCSS with strengthened end cap area will be studied to prevent similar failure.

Formation sand production is one of the major production challenges in most of the mature fields in Malaysia. Often, failure in primary sand control equipment requires the operators to adopt through-tubing sand screens as a remedial sand control. Current remedial sand control techniques utilizing metallic through tubing sand screens experience rapid wear, forcing the operator to control sand production by beaning down wells and thereby managing sand production at surface, in worst cases wells have to be shut-in. More robust technologies replacing conventional metallic screens are required. For these applications, alternative technology with ceramic sand screens have been deployed to enable higher productivity and offer enhanced resistance against erosion. Ceramic sand screens passed through a technical qualification process at Petronas and deployed in field applications both in oil and gas producers for through tubing interventions. To date 30 well interventions have been performed in various Petronas assets of Offshore East Malaysia with mixed results. Eight screen failures were observed with longevity ranging from 2.5 days to 15 months of production after installation. On average, ceramic sand screens greatly enhanced productivity return through longer performance than the conventional through tubing metallic screens from previous deployments. However, it was both the intent of product provider and Petronas to further improve Through Tubing Ceramic Sand Screen (TTCSS) performance based on the lessons learned from these failures. The TTCSS failures were first presented in the paper: SPE 196479 MS published at SPE APOGCE October 2019, Bali, Indonesia which which focused on the failures of these first generation TTCSS screen designs. This paper describes in more detail the value driven process and collaboration steps between 3M and Petronas to improve TTCSS field performance as a methodology to increase incremental field production to further increase longevity of downhole sand control in these applications. To enable this goal, a root cause analysis process entailed involving tear down investigation, hypothesis of failure characteristics, application review and investigation analysis with tools such as CFD and laboratory testing resulting in the implementation of ceramic sand screen design enhancements to improve performance in further Petronas deployments.

Downhole sand control selection plays a vital role in sand free production optimization over the well lifecycle. Design and selection criteria to assess the optimum sand control methodology requires consideration of many inputs to assess the sand control service life. A qualified sand control method, offering high erosion resistance is critical to enhance service life, especially in cases where small particles may be entrained in the produced fluids at high velocity. An integrated approach considering advances in filter media material, allow integration of ceramic components, to redefine operating envelope of sand control screen. In the process of designing and selecting a suitable sand control method for a high-rate gas well application in Norway, ceramic sand screens were considered as a possible solution to manage the high erosion loading expected during production. To estimate the operational limits for stand-alone ceramic sand screens, a series of erosion tests were conducted by a third party research and testing agency defined by the operator to evaluate the erosion behavior of the ceramic filter element. As indicator for erosion the filtration cut point (FCP) of the ceramic filter element was used. The testing allowed the operating envelope of the ceramic screens to be defined in terms of FCP and erosion load. For a specific increase in FCP value the operational limits for a stand-alone ceramic sand screen can estimated. This methodology was then applied to a specific field application to predict ceramic sand screen lifetime for the expected production profile. This paper presents the results of the study, using CFD simulations and, independent industry testing methodology to investigate the suitability and expected service life for stand-alone ceramic sand screen. Understanding the operational erosion risk profiling enables the operator to apply an erosional resistant stand-alone screen approach offering reducing planning, deployment complexity, lower HS&E risk and increased flexibility in optimising the wells production envelope.

Sand production remains as one of the most challenging complications in managing mature fields in Malaysia. More than half of the wells in Malaysian fields are completed with downhole primary sand control or require sand management throughout their lifetime. To further aggravate the issue, most primary sand controls installed have suffered from failure after an extended period of production. Thus, operators are often compelled to rely on thru-tubing metallic sand screens to reactivate idle sand wells. However, most metallic sand screens suffer from sustainability issue due to substantial erosion especially for those installed in wells with high gas flow rate. Therefore, alternative technology such as through-tubing ceramic sand screen (TTCSS) has been considered and applied due to its higher durability and resistance against erosion. This paper will discuss the evolution of TTCSS design and performance improvement in terms of longevity. Field application in Malaysian mature fields has shown that ceramic sand screen demonstrates a longer lifetime when compared to conventional metallic sand screen. However, to further improve the mean time between failures (MTBF) of TTCSS, extensive studies have been conducted by carrying out detailed teardown investigation and computational fluid dynamic (CFD) simulation. Design changes have been proposed and incorporated to mitigate the erosion risk at end cap area based on previous well installation. The enhanced TTCSS were then installed in the same well with high erosional velocity as pilot testing. The operating well envelope and installation method were maintained following the previous installation. TTCSS with enhanced design were then retrieved after a period of three months for detailed evaluation. Several criteria have been identified as key performance indicators for the success of enhanced TTCSS design. Throughout the pilot testing period, sand production at surface has been closely monitored to detect any sand grains larger than screen slot sizing. Upon retrieval, enhanced design of TTCSS shall not exhibit similar erosion patterns at end cap area which will affect the integrity of spring compensator system and cause the screen to lose its filtration mechanism. Lastly, enhanced TTCSS design shall prevent parting of screen during retrieval, reducing the risk of leaving the screen downhole as fish. This paper will present the outcome of pilot testing of enhanced TTCSS by comparing the performance with the original design using both teardown investigation and velocity calculation. Suggestion for further optimization will also be discussed to ensure TTCSS remains as one of the competent candidates for remedial sand control which can offer greater durability and longevity.