Drilling the reservoir section in the Sagari field (Peru) presents many challenges, such as wellbore collapsing in the extremely mechanically unstable Shinai formation; differential sticking in low-pressure, high-permeability sandstone reservoirs; and total losses due to the presence of natural fractures. This paper describes how the implementation of automated managed pressure drilling (MPD) and managed pressure cementing (MPC) techniques allowed overcoming those challenges in a remote location where logistics and equipment mobilization is an additional challenge. The preliminary geomechanical study indicated that an equivalent density (ED) of 10.5-lbm/gal was required to maintain wellbore stability, while 10.8-lbm/gal could not be exceeded due to the risk of differential sticking. Additionally, eliminating pressure variations in the mechanically unstable Shinai formation would prevent wellbore collapse. The MPD strategy for drilling the original 8.5-in hole section and sidetrack consisted in using an automated MPD System to maintain the ED profile within the 10.5 to 10.7-lbm/gal window along the open hole and a near-constant pressure of 10.5-lbm/gal in the most unstable Shinai formation at all times. Due to its reduced footprint, this automated MPD equipment package could easily be airlifted by helicopter to the remote rigsite. The MPD strategy was implemented as per plan; it successfully prevented wellbore instability and differential sticking and contributed to the excellent condition of the wellbore. Indeed, the production liner was run down the 2,700ft of open hole smoothly in less than six hours and later well testing revealed that the mechanical skin factor in the reservoir section was equal to zero. When drilling the last feet of the sidetrack with an ED of 10.5-lbm/gal, a natural fracture was encountered; it was immediately detected by the MPD Coriolis flow meter located at the well returns, allowing for a quick response and curing losses rapidly. However, this further reduced the operating window size. MPC allowed using a statically underbalanced drilling fluid, while ensuring well integrity and preventing wellbore collapsing during cement placement. The estimated ED on bottom was monitored in real-time and losses were successfully prevented. The coupling of the wiper plug on the landing collar was observed as per plan, and successful zonal isolation was later confirmed by cement bond log (CBL) and casing integrity test (CIT). In addition to the application of managed pressure techniques in the production section, MPC of the intermediate 9 5/8-in casing was performed as a contingency measure, as the reduced annular flow area between the two casing strings and the narrow pore pressure -fracture pressure window would not allow cementing the casing conventionally.
The objective of this study is to evaluate the quality of service of delivery applications, in order to have knowledge of which factors are most important for consumers when making their online purchase process and how much influence these factors have on the purchase process. consumer loyalty. Therefore, a quantitative study was carried out through a survey that uses several measurement models such as ESQUAL. This survey was applied online to 319 residents of the city of Guayaquil who use delivery applications. In th e analysis of the results, the data was divided into three groups: "General", "Uber Eats" and "Other apps", to evaluate the behavior of the variables of each group by estimating a Structural Equation Model. Among the main results, it is highlighted that the variables Guarantee, Personalization, Relationship with the brand and Traceability have a positive and significant effect on the loyalty of users of delivery apps and that "Uber Ea t s"is the market leader despite that its users consider that the shipping cost is somewhat high.
No abstract
The Talara Basin in Perú is a mature oil field where production is extremely marginal, and well-construction designs are tailored to this condition to optimize well costs. However, one well recently drilled in this area was identified with the original reservoir pressure, and the well design was not based on this pressure. As a result, drilling issues such as fluid loss and lost circulation were carefully monitored while trying to control reservoir pressure in a long open-hole section. The challenges faced while cementing a high-pressure zone with controlled fluid losses and achieving well objectives in terms of safety, reliability, and lifetime zonal isolation of the well are discussed. At the planning stage, a mud density of 13 lbm/gal was considered adequate to control downhole pressure (overbalanced); however, before reaching total depth, signs of high pressure were observed while drilling through a low-permeability formation. Mud density was significantly increased to control the well while monitoring the fluid return. When the mud weight reached 15.5 lbm/gal, losses were reported. Finally, the well was stabilized at 15.8 lbm/gal using different lost circulation pills. This event complicated the cementing operation because it substantially increased the necessary slurry density (16.1-lbm/gal lead and 17-lbm/gal tail). Nevertheless, proper cementing design and effective slurry placement using conventional techniques resulted in successful cementing operation with full cement return to the surface. High-density cement slurries were successfully mixed and pumped regardless of their highly viscous property. The cementing unit and personnel were able to manage this vital operation without facing major problems. Before bumping the plug, circulating pressure was close to the theoretical value, confirming that the cement slurry column was as per the design without noticeable losses into the formation. Full cement returns confirmed a successful cement placement. Final circulating pressure was 2,370 psi, and it increased to 2,900 psi when the plug was bumped. The cement evaluation log obtained after 24 hours indicated good bonding, effective mud displacement, and a successful cement operation. The well was then fractured and put on production. Neither corrective work nor a well-integrity remediation operation was necessary. Drilling the abnormally pressurized well was extremely challenging because of unexpected high pressure and associated problems, including working with high-density slurries and using various fluid additives to achieve adequate zonal isolation for future stimulation works. Techniques involved and experiences gained while undertaking this considerably challenging project are discussed in this article.
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