Successful Gas Shutoff Operation Using a Coiled Tubing Telemetry System: A Case History

2021 ◽  
pp. 1-15
Author(s):  
A. Amirov ◽  
F. Hadiaman ◽  
D. Parra ◽  
J. Zeynalov ◽  
A. Kok

Summary In a deviated well in the Caspian Sea, the gas/oil ratio (GOR) increased rapidly in 2017. The result was an oil rate decline with several choke backs to manage GOR buildup. After performing two production-logging jobs, it was confirmed that 76% of the gas production was coming from four upper perforations. The main objective was to perform a gas shutoff (GSO) treatment in two stages to reduce gas production by squeezing polymer into the formation and setting packers at a 59° deviation inside a 9⅝-in. casing for temporary isolation of the middle and lower production sands. Fifteen runs were performed with a tube wire-enabled coiled tubing (CT) telemetry (CTT) system that consists of a customized bottomhole assembly (BHA) that instantaneously transmits differential pressure (DP), temperature, and depth data to the surface through a nonintrusive tube wire installed inside the CT. For the first time in the region, a tension, compression, and torque (TCT) subassembly was deployed to control the entire setting/retrieval process with accurate downhole upward/downward forces. CTT technology was a key element to successfully set two through-tubing inflatable retrievable packers (TTIRPs) by performing casing collar locator correlations at the tubing end, which was 133 and 228 m [measured depth (MD)] shallower from the setting depths. In addition, during the second GSO operation, the GSO gel system crosslink time was modified on the basis of the actual bottomhole temperature (BHT) recorded with the CTT system. Finally, during the third GSO operation, treatment placement was improved, spotting more GSO gel system inside the casing section and avoiding further treatments. After successful placement of the GSO gel system, a drop from 15.5 to 4.5 MMscf/D in gas production was observed (GOR reduction from 11,000 to 750 MMscf/bbl) with an oil rate increment from 1.4 to 6.04 Mbbl/D. Furthermore, after the gas reduction, the operator was able to produce between 1.5 and 2.0 Mbbl/D from other wells that were choked back on the basis of gas handling capabilities limitations. In the short term, GOR reduction sustained at 3,000 MMscf/bbl and 3.0 Mbb/D oil rate. The novelty of using the CTT system and TCT subassembly for real-time monitoring of BHA data proved to be beneficial for positioning two TTIRP, modifying GSO gel system design, placing it precisely across target intervals, and retrieving two TTIRPs that in the end provided direct and positive financial impact for the operator.

2021 ◽  
Author(s):  
A.. Amirov ◽  
F.. Hadiaman ◽  
D.. Parra ◽  
J.. Zeynalov ◽  
A.. Kok

Abstract In a deviated well in Caspian Sea gas oil ratio (GOR) increased rapidly in 2017. The result was an oil rate decline with several choke backs to manage GOR build-up. After performing two production-logging jobs, it was confirm that 76% of the gas production was coming from four upper perforations. The main objective was to perform a Gas Shut off (GSO) treatment in two stages to reduce gas production by squeezing polymer into the formation and setting packers at 59° deviation inside 9-5/8 in. casing for temporarily isolation of middle and lower production sands. Fifteen runs were perform with a tube wire-enabled CT telemetry (CTT) system which consists of a customized bottomhole assembly (BHA) that instantaneously transmits differential pressure, temperature, depth data to surface through a non-intrusive tube wire installed inside the CT. For the first time in the region, a tension, compression and torque (TCT) sub-assembly was deploy to control the entire set/retrieve process with accurate downhole upward/downward forces. CTT technology was a key element to successfully set two Thru Tubing Inflatable Retrievable Packers (TTIRP) by doing casing collar locator (CCL) correlations at tubing end which was 133 m and 228 m (MD) shallower from setting depths. In addition, during second GSO operation, polymer crosslink time was modify based on actual bottomhole temperature recorded with CTT system. Finally, during third GSO treatment placement was improve spotting more GSO system in casing section avoiding further treatments. After successful placement of the GSO system, a drop from 15.5 to 4.5 MMscf/day in gas production was observed along with GOR reduction from 11,000 to 750 MMscf/bbl and oil rate increment from 1.4 to 6.04 Mbpd. Furthermore, after gas reduction operator was able to produce between 1.5 to 2.0 Mbpd from other wells that were choke back based on gas handling capabilities limitations The novelty of using the CTT system and TCT sub-assembly for real-time monitoring of BHA data was proven for not only positioning two TTIRP, modifying polymers crosslink design, placing polymer precisely across target intervals and retrieve two TTIRP that at the end provide direct and positive financial impact for the operator.


2021 ◽  
Author(s):  
Mikhail Yurievich Golenkin ◽  
Denis Vladimirovich Eliseev ◽  
Alexander Anatolyevich Zemchikhin ◽  
Alexey Alexandrovich Borisenko ◽  
Akhmat Sakhadinovich Atabiyev ◽  
...  

Abstract The paper describes the results of the first multistage hydraulic fracturing operations in Russia on the Caspian Sea shelf in the gas condensate and oil deposits of the Aptian formation of V. Filanovsky field. In addition to the small productive formation depth, long horizontal sections with a complex trajectory and high collapse gradients due to large zenith angles when passing the Albian and Aptian deposits of poorly consolidated sandstones are an additional challenge for choosing a multistage hydraulic fracturing assembly. The above features require the use of modern sand control screens with enhanced frac sleeves. A design was developed which includes frac sleeves and sand control screens that can withstand multiple cycles of hydraulic impact during hydraulic fracturing, as well as many opening/closing cycles. A seawater-based frac fluid system was applied. The frac fleet was located on a pontoon, the coiled tubing – on a platform. For the first time in Russia, a 2-5/8 inch coiled tubing with a complex-type friction reducing system was used to switch coupling/sleeves in conditions of very long horizontal sections, complex trajectories, and high friction coefficients. The minimum distances between the screen's sliding sleeves and frac sleeves did not prevent from performing manipulations in complex environment. For well cleaning, the frac assemblies of reverse rotary-pulse and rotary-directional types were used. At the first stage of the project, the development of an optimal method of well completion was successfully implemented. Due to the close interaction of the operating company, service company, and science & engineering team of the operator, for the first time in Russia the design of downhole equipment with the use of advanced technologies of sand control screens, frac sleeves was presented. This solution has proved its effectiveness – the downhole equipment has retained its operational properties after a long period of well operation and further in the process of hydraulic fracturing. At the second stage of the project, 32 MSHF operations were performed at four wells. To reduce nonproductive time and operational risks, a satellite communication complex was additionally deployed on the pontoon to join the engineering centers of Astrakhan, Moscow, and Houston. After finishing the well development, the design indicators for formation fluid rates were achieved, which proved the effectiveness of the stimulation of the field's target objects – this opens great prospects for further development of low-permeability reservoirs at offshore sites in the Caspian Sea. The successful project implementation and the achievement of the design values of oil flow rates has expanded the possibilities of commercial operation of the low-permeable Aptian formation, complicated by the presence of a gas cap and underlying water. A solution was presented for working in extended horizontal well sections with 2-5/8 inch coiled tubing together with a complex-type mechanical friction reducing system. The economic effect was achieved when solving tasks of manipulating mechanical screen couplings and frac port sleeves without the involvement of downhole tractors. The use of new solutions in the completion assembly made it possible to eliminate additional sand ingress problems.


2021 ◽  
Author(s):  
Charlie A. McClean ◽  
David Enrique Parra ◽  
Alexander Piven ◽  
Khalid Rahimov ◽  
Farid Hadiaman

Abstract Over the past years the usage of coiled tubing as a prefer method to deploy long and heavy guns in highly deviated wells has been widely spread in the oil industry to provide a single run without killing the well, perforate in underbalance conditions, reduce risks and improve job efficiency. The three wells are located in the Caspian Sea. In two wells, the objective was to isolate lower intervals and perforate a new zone through tubing and casing between two packers. On the other well, the objective was to perforate a new interval through casing after running a new completion and isolate lower production zones. Due to the challenges involving gross length of the new intervals, guns size, well deviation and live deployment needs several techniques were evaluated. The best approach was to use an Advance Live-Well Deployment (ALWD) system to deploy and retrieve the guns with a tube wire-enabled Coiled Tubing Telemetry (CTT) system focus on both safety and cost saving compare with conventional wireline perforating. Extensive job planning involved coiled tubing (CT) simulations to reach target depths, shock loading modeling to ensure forces are within CT string limitations, system integration test to verify deployment/reverse technique procedure and system communication to electrically activate guns. CTT integrated sensor assembly was used during deployment/reverse operation with a tension, compression and torque (TCT) sub-assembly to monitor accurate upward/downward forces. In addition, CTT logging adapter assembly was used for depth correlation and electrical guns activation. The ALWD system; composed by connectors and deployment blow out preventor (BOP), prove to be an efficient way to run, perforate and retrieve gross intervals of 212 m, 246 m and 104 m with guns successfully. During all these jobs several lessons learnt were created in order to improve the deployment/reverse procedure for future jobs including not only operational steps but also deployment/reverse bottom-hole assembly (BHA) configurations. Based on the success of these case histories, the ALWD combined with CTT system has been proven to be the preferred method when dealing with long perforation intervals in life well conditions, thru-tubing environment.


Author(s):  
G. O. Hutchinson

The chapter looks at the division between poetry and prose in ancient and other literatures, and shows the importance of rhythmic patterning in ancient prose. The development of rhythmic prose in Greek and Latin is sketched, the system explained and illustrated (from Latin). It is firmly established, for the first time, which of the main Greek non-Christian authors 31 BC–AD 300 write rhythmically. The method takes a substantial sample of random sentence-endings (usually 400) from each of a large number of Imperial authors; it compares that sample with one sample of the same size (400) drawn randomly from a range of authors earlier than the invention of this rhythmic system. A particular sort of X2-test is applied. Many Imperial authors, it emerges, write rhythmically; many do not. The genres most likely to offer rhythmic writing are, unexpectedly, narrative: historiography and the novel.


Author(s):  
Tania Pantazi

The increase in short-term rentals via online platforms has captured the attention of scholars and regulators. Short-term letting is now considered a considerable alternative to traditional tourist accommodation contracts, challenging matters such as conditions in the housing market and consumer protection. Online platforms, such as Airbnb, Booking.com , Expedia and Tripadvisor, now provide offers for short-term accommodation contracts along with traditional accommodation options (hotels, hostels, apartments). The recent decision of the European Court of Justice in Joined cases C-724/18 and C-727/18 addresses for the first time the issue of regulation of short-term rentals in Member States and evaluates a national authorization scheme in light of the Services Directive. The present paper provides a brief background of European regulation affecting short-term rentals and discusses the judgment and its implications for future developments.


2015 ◽  
Author(s):  
Ali Daneshy ◽  
Chad Touchet ◽  
Fred Hoffman ◽  
Mike McKown

Abstract This paper presents the analysis results of 60 single stage fracturing treatments performed in a horizontal well using cemented casing sleeves and a coiled tubing deployed frac isolation system as the completion method. In this carefully set-up and executed treatment, separation between the toe stages was 97 feet, and near the heel it was 55 feet. Pressure data was collected above and below the retrievable plug used for stage isolation. This data was used for analysis of fracturing treatment data which included mode of propagation, completion efficiency, and a rough estimate of fracture orientation. The analysis showed that; There was no interaction between adjacent fractures during five of the sixty fracturing stages. None of these was in the well interval with shorter fracture spacingFracture shadowing occurred during six fracture stages, again none in the shorter spacing intervalMinor cement defects (micro-annuli) caused some fluid migration into the passive segment of the well. This happened in 27 stages. Of these; In eleven cases the cement defects were plugged after a while, causing the migration of fracturing fluid into the passive interval to stop.In sixteen other cases the fluid migration through cement micro-annuli continued during fracturing.During ten stages, defective zone isolation and fluid migration caused a pressure increase of several hundred psi in the passive segment of the well. But this did not result in extension of passive fractures.The volume of migrated slurry due to inadequate zone isolation was mostly a very small fraction of the injected volume.During five stages poor cement quality hampered stage isolation and caused immediate link between adjacent active and passive intervals and extension of passive fractures.The data indicate possible connection between the active and one passive fracture in four stages.Shorter spacing between stages increased the incidents of fluid migration due to poor cement qualityThe fracturing pressure variations during the treatments did not indicate presence of large stress shadowingA rough estimation of fracture orientation indicates that they were likely to be vertical and nearly perpendicular to the wellbore.The fracture growth pattern can best be described as off-balance. To our knowledge, this is the first time existence of direct communication between adjacent fractures has been observed through actual pressure interference data.


2017 ◽  
Vol 28 (5) ◽  
pp. 615-635
Author(s):  
Semra Atasayar ◽  
Sevil Guler Demir

This descriptive, cross-sectional study investigated problems experienced by patients after undergoing a thyroidectomy. The study included 60 first-time, post-thyroidectomy patients diagnosed with benign thyroid disease from a university hospital’s general surgery clinic in Ankara, Turkey. The data were collected in two stages: interviews with patients on the first day following surgery and postoperative follow-up telephone interviews in each of the first 4 weeks following surgery. The follow-ups revealed that patients principally experienced varying degrees of pain and difficulties in connection with work and recreation, communication, body image, and movement, for up to 4 weeks after surgery. These results showed that patients were particularly prone to problems on the first day and during the first week of the postoperative period; therefore, patients should be provided with follow-up telephone interviews to facilitate easier recovery and to help them overcome any problems experienced during the postoperative period.


2021 ◽  
Vol 11 (19) ◽  
pp. 8880
Author(s):  
Bowen Guan ◽  
Cunbo Fan ◽  
Ning An ◽  
Ricardo Cesar Podesta ◽  
Dra Ana Pacheco ◽  
...  

As one of the major error sources, satellite signature effect should be reduced or even erased from the distribution of the post-fit residuals to improve the ranging precision. A simulation of satellite signature effect removal process for normal point algorithm is conducted based on a revised model of satellite response, which fully considers the structural and distribution characteristics of retroreflectors. In order to eliminate both long-term and short-term satellite signature effect, a clipping method for SLR data processing is proposed by defining the clipping location as 5.6 mm away from the mean value of the long-term fit residuals to select effective returns for normal points. The results indicate that, compared to normal points algorithm, the RMS per NP of LAGEOS-1 observation data processed by the clipping method is reduced from 62.90 ± 9.9 mm to 56.07 ± 4.69 mm, and the stability of RMS is improved 53%. This study improves the satellite signature effect model and simulates the fluctuation of normal points caused by satellite signature effect for the first time. The new method based on the simulation of satellite signature effect has stronger robustness and applicability, which can further minimize the influence of satellite signature effect on the SLR production and significantly improve the data property.


2011 ◽  
Vol 8 (5) ◽  
pp. 9847-9899 ◽  
Author(s):  
D.-G. Kim ◽  
R. Vargas ◽  
B. Bond-Lamberty ◽  
M. R. Turetsky

Abstract. The rewetting of dry soils and the thawing of frozen soils are short-term, transitional phenomena in terms of hydrology and the thermodynamics of soil systems. The impact of these short-term phenomena on larger scale ecosystem fluxes has only recently been fully appreciated, and a growing number of studies show that these events affect various biogeochemical processes including fluxes of soil gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ammonia (NH3) and nitric oxide (NO). Global climate models predict that future climatic change is likely to alter the frequency and intensity of drying-rewetting events and thawing of frozen soils, highlighting the importance of understanding how rewetting and thawing will influence soil gas fluxes. Here we summarize findings in a new database based on 338 studies conducted from 1956 to 2010, and highlight open research questions. The database revealed conflicting results following rewetting and thawing in various terrestrial ecosystems, ranging from large increases in gas fluxes to non-significant changes. An analysis of published field studies (n = 142) showed that after rewetting or thawing, CO2, CH4, N2O, NO and NH3 fluxes increase from pre-event fluxes following a power function, with no significant differenced among gases. We discuss possible mechanisms and controls that regulate flux responses, and note that a high temporal resolution of flux measurements is critical to capture rapid changes in gas fluxes after these soil perturbations. Finally, we propose that future studies should investigate the interactions between biological (i.e. microbial community and gas production) and physical (i.e. flux, diffusion, dissolution) changes in soil gas fluxes, and explore synergistic experimental and modelling approaches.


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