{"id":20170,"date":"2021-08-24T16:08:30","date_gmt":"2021-08-24T16:08:30","guid":{"rendered":"https:\/\/ihttpdev.co.uk\/merlin\/?p=20170"},"modified":"2021-08-24T16:08:30","modified_gmt":"2021-08-24T16:08:30","slug":"friday-haggler-6","status":"publish","type":"post","link":"https:\/\/merlinerd.com\/es\/2021\/08\/24\/friday-haggler-6\/","title":{"rendered":"Friday Haggler 6"},"content":{"rendered":"<h1 class=\"reader-article-header__title t-40 t-black t-normal pv4\" dir=\"ltr\">Friday Haggler<\/h1>\n<h2>A reminder of last Friday&#8217;s Haggler<\/h2>\n<p>You have just finished drilling an 8-\u00bd\u201d high-angle reservoir section, which is known to have intervals that are susceptible to weak bedding-plane failure. A full clean-up cycle has been performed, but residual cuttings\/cavings beds are known to exist, with several over-gauge zones. The next operation will be to run a 7\u201d liner to TD. Based on the data shown on the fixed-depth (TD) swab\/surge model, which of the following tripping options would be safest overall? Assume a pulling speed of 3 minutes per stand (range 2 drill pipe), except where otherwise stated.<\/p>\n<p>A. Pull on elevators at 1 minute per stand<br \/>\nB. Pump out (no rotation) with 450gpm<br \/>\nC. Pull on elevators at 3 minutes per stand in open hole, increasing speed in cased hole<br \/>\nD. Pump out (no rotation) with 50gpm<br \/>\nE. Back-ream out of open hole with parameters used to drill (450gpm, 100rpm)<br \/>\nF. Pump out (no rotation) at 100gpm &amp; 10 minutes per stand<\/p>\n<h2><img decoding=\"async\" class=\"alignnone wp-image-20171 size-full\" src=\"https:\/\/merlinerd.com\/wp-content\/uploads\/2021\/08\/1625226495917.jpg\" alt=\"\" width=\"581\" height=\"822\" srcset=\"https:\/\/merlinerd.com\/wp-content\/uploads\/2021\/08\/1625226495917.jpg 581w, https:\/\/merlinerd.com\/wp-content\/uploads\/2021\/08\/1625226495917-212x300.jpg 212w\" sizes=\"(max-width: 581px) 100vw, 581px\" \/><\/h2>\n<h2>The Answer<\/h2>\n<div><\/div>\n<p><strong>Short Answer<\/strong>: D<\/p>\n<p><strong>Long Answer<\/strong>: While POOH on elevators is preferable the model swab pressures rule out A and C. Pumping out at drilling flow rates will move at least some of the cuttings to above the BHA, creating a high pack-off risk, ruling out B. Backreaming (E) is best avoided, if possible, especially in this case where instability has been identified as a problem. This leaves pumping out with low flow (lubricating) to neutralise the swab effect. It is also important to define a maximum flow rate to avoid the same problem as discussed above for B. The maximum lubricating flow rate needs to be calculated for a specific pulling rate. While there are various methods to do this, ranging from open-ended pipe displacement to open-hole volume, it is best to use the latter as a means of determining the maximum to avoid upward flow past the BHA. If pumping 100gpm at 10 min\/std, you are over-displacing the open hole volume by 73 gpm, which is enough to mobilise cuttings and increase the pack-off risk, ruling out F. 50 gpm is more than enough to eliminate the overall swab effect, while avoiding over-displacing the open hole and mobilising cuttings. D is the best option. No space to share calcs unfortunately<\/p>","protected":false},"excerpt":{"rendered":"<p>Friday Haggler A reminder of last Friday&#8217;s Haggler You have just finished drilling an 8-\u00bd\u201d high-angle reservoir section, which is known to have intervals that are susceptible to weak bedding-plane<\/p>","protected":false},"author":6,"featured_media":20171,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-20170","post","type-post","status-publish","format-standard","has-post-thumbnail","category-friday-haggler"],"_links":{"self":[{"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/posts\/20170","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/comments?post=20170"}],"version-history":[{"count":0,"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/posts\/20170\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/media\/20171"}],"wp:attachment":[{"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/media?parent=20170"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/categories?post=20170"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/merlinerd.com\/es\/wp-json\/wp\/v2\/tags?post=20170"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}