Roller-Cone Core Barrels

Ngwá ọrụ roller-cone core barrels bụ ngwá ọrụ ịkpụ rotary pụrụ iche e mere iji nweta ihe atụ nke rock core nke na-anọchite anya ngwa ngwa site na ngwa ụlọ ala, karịsịa maka nyocha rock socketing na njirimara ala n'ime nnukwu excavation na ọrụ imezi ala. Ngwá ọrụ ndị a nwere cylindrical barrel nwere core tube n'ime na rotary head assembly nke etinyere roller-cone bits—nke a na-ahụkarị bụ cone atọ na-agba ọsọ nke nwere steel siri ike ma ọ bụ tungsten carbide-tipped cones nke etinyere tungsten ma ọ bụ diamond inserts. Core barrel na-eme ka njikọ ụlọ dị n'etiti drilling string na cutting head, na-enye ohere ka a nweta ihe ndị a na-enweta site na rock na a na-enweta ya n'ozuzu maka nyocha geology na geotechnical. Ngwá ọrụ roller-cone core barrels na-arụ ọrụ na ọtụtụ usoro ụlọ ala: na nrụpụta diaphragm wall, ebe ịdị elu na àgwà nke bedrock na-achịkwa nkwado excavation na ikike pile socket; na secant na tangent pile walls, iji nyochaa ịdị elu rock socketing na njirimara bearing stratum; na cutoff curtains na seepage control structures, iji nyochaa permeability na grout take zones na oghere grouting nwere ike; na nyocha saịtị mbụ na drilling tupu nnukwu excavation ma ọ bụ underpinning ọrụ. Ọrụ ha bụ inye njikwa core recovery na Rock Quality Designation (RQD) edere, uniaxial compressive strength testing, na njirimara fracture dị mkpa maka nkwenye imewe na nkwado àgwà. Usoro ọrụ na-adabere na torque na-agba ọsọ nke etinyere na drill string, na-eme ka roller cones na-agba gburugburu axis core barrel mgbe a na-eme ka ha pụọ na ihu rock. Ihe na-egbutu bụ isi na-agbaji na ịkpụ—ọnụ cone ọ bụla na-agbaji ihe rock n'okpuru roller-cone bit, na-enye ohere ka ihe a na-agbaji na-adaba n'ime core tube n'ime. Ka drilling na-aga n'ihu, akụkụ barrel na-abawanye n'otu akụkụ na-ejide rock column, nke a na-edebe site na core catcher (ball ma ọ bụ basket type) nke na-arụ ọrụ site na ibu. Ozugbo a nwetara ogologo core achọrọ (nke a na-ahụkarị bụ 3–10 mita kwa ọsọ), a na-ewepụ ngwá ọrụ niile ma a na-ewepụ core ahụ n'ụzọ dị mma, tụọ, dekọọ, ma kwadebe ya maka nyocha laboratory dị ka ISRM (International Society for Rock Mechanics) ụkpụrụ. Ngwaọrụ nhazi gụnyere usoro wire-line ọkọlọtọ (NQ, HQ, PQ gauge sizes nke na-ezute 47.6, 63.5, na 85 mm core diameters) na conventional rod-suspended barrels. Ngwaọrụ roller-cone bit na-agbanwe site na nkewa siri ike nke rock: ihe ndị dị nro na-eji carbide-tipped inserts na nnukwu cone spacing, mgbe rock siri ike ma ọ bụ abrasive chọrọ tungsten carbide button bits na nso nso button density. Extended-length barrels maka strata dị thick, split-tube barrels maka nchekwa ihe atụ ka mma, na sistemụ core nke a haziri ahazi maka nyocha geology ụlọ bụ ụdị ndị a na-ahụkarị. Nhọrọ nke nhazi roller-cone core barrel dabere na ike rock a na-atụ anya (UCS range), ihe achọrọ maka recovery core nke a kọwara na scope nyocha geotechnical, mmefu ego drilling, na nkwado na ike nke rig. Ndị na-eme drilling ga-enwerịrị njikọ dị n'etiti àgwà recovery na ọsọ drilling—ịkụda nke na-agba ọsọ na-eme ka penetration na-arị elu ma na-eme ka ihe atụ core dị n'ọnọdụ; usoro na-echekwa na-eme ka fracture dị ala ma na-agbakwunye oge ọrụ. Ụkpụrụ ndị a na-ejikarị bụ ISO 13311-1 (oriented core na njirimara rock mass), DIN 4095 (ụkpụrụ German maka boring na coring), na API (American Petroleum Institute) nduzi nke a haziri maka ngwa ụlọ. Nyocha RQD na-esochi ntụziaka ISRM, na foto core na nchekwa core box edere dịka ISO 14689 ụkpụrụ.