Strategy Targets Risk Management for CO2 Waterless Fracturing

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 30437, “Risk Management and Control for CO2 Waterless Fracturing,” by Siwei Meng, Qinghai Yang, SPE, and Yongwei Duan, PetroChina, et al., prepared for the 2020 Offshore Technology Conference Asia, originally scheduled to be held in Kuala Lumpur, 2–6 November. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission. Given shortages and uneven distribution of water resources in China, efforts must be made to develop waterless fracturing techniques. The fluid experiences high pressures and low temperatures during carbon dioxide (CO2) waterless fracturing operations, which can lead to accidents and environmental pollution. In the complete paper, a safety-management approach and a contingency plan for such operations are developed. At the time of writing, this CO2 waterless fracturing methodology has been completed successfully more than 20 times. Surface Process Work Flow of CO2 Waterless Fracturing The basic process of a CO2 waterless fracturing operation is shown in Fig. 1. First, several CO2 storage tanks are connected in parallel. The booster, sealed blender, fracturing pump (all mounted on trunks), and wellhead equipment are connected. The measuring trunk communicates with each vehicle to monitor operation status. Proppant is put into the sealed blender, into which liquid CO2 is injected for pre-cooling. Pump testing is conducted on the high-pressure line and the wellhead and the low-pressure liquid supply line is pressure-tested. Operation does not proceed until pressure-testing results are positive. Afterward, liquid CO2 is injected into formations to fracture them and, moreover, extend created fractures. The sealed blender is enabled to inject prop-pants, and displacement begins after the end of proppant injection. Finally, a series of tasks, including well shut-in for soaking and flowback, is carried out successively.

The Manufacturing Planning of Installation Series-Parallel Combination Centrifugal Pump Testing Equipment

This study discusses the planning in making a centrifugal pump installation with a combination of two series, namely series and parallel. The concept of discussion refers more to the upgrading of the installation system and calculates the estimated processing time needed to test the performance of the results of the installation that has been made. From the results of the research, it was found that for the preparation of series series installation it takes ± 8.5 minutes including the cutting process of materials and component installation, while the time required in making the installation of parallel circuits ± 28 minutes so that the total manufacturing of the two types of series takes 36, 5 minutes. In terms of performance generated from each installation obtained at full aperture where for the series of head series the value obtained is 37.6 m with a flow capacity of 3.25 l / s while for the head value on the parallel pump obtained by 27.7 m with a capacity flow of 3.75 l / s and this pump operates at 2900 rpm. So it can be seen from the results of the head and flow capacity obtained values ​​indicate good pump performance and ready to be used as a practical tool in the laboratory.

Pengujian Kinerja Pompa Sentrifugal Multistage Berkapasitas 118,5 KW pada PLTP Berdasarakan Standar ISO 9906

AbstrakPengujian unjuk kerja pompa sentrifugal multistage berkapasitas 118,5 kW di kawasan Pembangkit Listrik Tenaga Panas Bumi (PLTP) daerah Jawa Barat saat ini akan menyesuaikan prosedur standar. Standar pengujian pompa diterapkan pada proses pengujian pompa dengan tujuan nilai hasil pengujian valid. Nilai head dan debit yang didapat dari pengujian dibandingkan dengan hasil pengujian sebelum penerapan standar. Pengujian pompa sentrifugal menerapkan metode pengujian lapangan dengan menerapkan standar ISO 9906-2012. Standar ISO 9906-2012 adalah panduan baku pengujian pompa rotodinamik. Dari hasil pengujian, didapatkan kurva pompa sentrifugal multistage debit maksimal 116,64 m3/h pada head 275,13 m. Pada data spesifikasi kapasitas pompa sebesar 108 m3/jam dan head total sebesar 300 m. Hal ini berarti prosedur pengujian pompa ISO 9906-2012 dapat memungkinkan kita untuk melihat kinerja pompa aktual.Kata kunci: pompa sentrifugal, pengujian lapangan, uji kinerja pompa, ISO 9906 AbstractPerformance test of multistage centrifugal pump at geothermal power plant area around west java is about to adapt standard procedure. Pump testing standards are applied during pump performance test in order to valid test result values. Head and flowrate value from current test compared with previous test result before standard are applied. Pump performance test use field test method by applying ISO 9906-2012 standard. ISO 9906-2012 standard is a normative guidance for rotodynamic pump testing. The test result shows multistage centrifugal pump curve maximum flowrate is 116,64 m3/h at total head 275,13 m. Pump specification sheet shows that maximum capacity is 108 m3/h and total head 300 m. It indicates that ISO 9906-2012 standard pump testing procedure allow us to determine actual pump performance.Kata kunci: Centrifugal pump, field test, performance test, ISO 9906

On-site investigation and forecast of changes in characteristics of ground water intake in time

The on-site investigation of groundwater intakes is carried out to obtain and update the actual parameters of the equipment and structures of a water intake, to optimize its operation modes with an analysis of their changes in time in order to plan maintenance and repair. This article discusses an improved methodology for examining individual elements and structures of groundwater intakes, which allows us to evaluate their current technical condition and to make a predictive calculation of changes in well productivity for the next period of operation based on the solution of the equations of dynamic equilibrium. The technique of clogging assessment allows determining ageing coefficients and approximate residual life of wells; the estimate of the rated pump pressure head reduction due to wear enables the pump testing during its operation at the well and timely replacement of the pump for routine repair; assessment of pipe sculling makes it possible to account for hydraulic resistance of lines connecting the wells to prefabricated water pipes during operation.

Deploying Elemental Iodine in a Vapor Form to Disinfect Water and to Clear Biofilms

Traditionally, iodine has been delivered as a solution, tablet or resin to disinfect water. In this study we evaluated the “I2 vapor infusion” (I2VP) technology which passes an airstream through a matrix containing elemental iodine (I2) to produce I2 vapor as an innovative method of iodine delivery for water disinfection. Pressured air was provided either by a compressor or hand pump. Testing was performed with water inoculated with either Gram-negative (Escherichia, Salmonella) or Gram-positive (Enterococcus) bacteria or with pre-formed Acinetobacter or Staphylococcus biofilms. Bacterial colony forming units were used to assess efficacy of the device. In distilled water all bacteria and biofilms were eliminated after brief exposures (<90 s). Culturable bacteria were also eliminated from pond and municipal sewer water, but the technology was mostly ineffective against dairy lagoon water with high turbidity and organic particulate. Longer duration infusion and higher air volumes used to overcome interference from organic matter were also associated with higher concentrations of residual iodine. We conclude that I2 vapor infusion has the potential to be useful for emergency water treatment and potentially for reducing microbiological contamination of some waste streams.