TY - THES

T1 - Drilling Problem Analysis in the Mittelplate field with Solution Proposals for Future Wells.

AU - Rothschedl, Markus

N1 - embargoed until null

PY - 2005

Y1 - 2005

N2 - In the past wells have been drilled into the Mittelplate reservoir from the artificial drilling island Mittelplate A as well as from shore. Within the scope of the future development, the length of the directional wells, drilled to the oil bearing Dogger Sands in 2000 to 3000m depth, will increase. Especially the reservoir parts in the west and south, which are located quite a distance away from Mittelplate A, are planned to be drilled with so called “Extended Reach” wells. The drilling problems in the Mittelplate field, especially from the lower cretaceous formation on, have increased in the past due to the increasing horizontal step out from the starting point and the increased inclination of the wells. With this master thesis those drilling problems have been identified and vulgarized by using a special drilling analysis program and by analysing the real time rig data. This analysis demonstrated that there has been a hole cleaning problem, which seems to be the cause for a subsequent wellbore stability problem. Thus proposed solutions for future wells have been worked out to present possibilities to avoid problems related to hole cleaning. As a solution the application of cutting bed impeller, pressure while drilling tools, cutting flux measurement, rotary steerable systems etc. are strongly recommended. Alternative solutions, such as solid expandable tubulars and casing drilling, have been identified to reduce the problems as well.

AB - In the past wells have been drilled into the Mittelplate reservoir from the artificial drilling island Mittelplate A as well as from shore. Within the scope of the future development, the length of the directional wells, drilled to the oil bearing Dogger Sands in 2000 to 3000m depth, will increase. Especially the reservoir parts in the west and south, which are located quite a distance away from Mittelplate A, are planned to be drilled with so called “Extended Reach” wells. The drilling problems in the Mittelplate field, especially from the lower cretaceous formation on, have increased in the past due to the increasing horizontal step out from the starting point and the increased inclination of the wells. With this master thesis those drilling problems have been identified and vulgarized by using a special drilling analysis program and by analysing the real time rig data. This analysis demonstrated that there has been a hole cleaning problem, which seems to be the cause for a subsequent wellbore stability problem. Thus proposed solutions for future wells have been worked out to present possibilities to avoid problems related to hole cleaning. As a solution the application of cutting bed impeller, pressure while drilling tools, cutting flux measurement, rotary steerable systems etc. are strongly recommended. Alternative solutions, such as solid expandable tubulars and casing drilling, have been identified to reduce the problems as well.

KW - Mittelplate Germany Wadden Sea Drilling Problems Genesis Drilling Analysis Cockpit Wellbore Stability Hole cleaning Rotary Steerable Systems Pressure While Drilling Tools Cutting Bed Impeller Cutting Flux Measurement Solid Expandable Tubulars

KW - Mittelplate RWE Dea Deutschland Wattenmeer Probleme

KW - bohrtechnische Genesis Drilling Analysis Cockpit Wellbore Stability Hole cleaning Rotary Steerable Systems Pressure While Drilling Tools Cutting Bed Impeller Cutting Flux Measurement Solid Expandable Tubulars Casing Drilling

M3 - Diploma Thesis

ER -