Novel Wellbore Strengthening Enables Drilling Of Exploration Well in a Highly Depleted Formation.

Author(s):  
Friday Otutu
Author(s):  
Flemming G. Christiansen ◽  
Anders Boesen ◽  
Finn Dalhoff ◽  
Asger K. Pedersen ◽  
Gunver K. Pedersen ◽  
...  

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Christiansen, F. G., Boesen, A., Dalhoff, F., Pedersen, A. K., Pedersen, G. K., Riisager, P., & Zinck-Jørgensen, K. (1997). Petroleum geological activities onshore West Greenland in 1996, and drilling of a deep exploration well. Geology of Greenland Survey Bulletin, 176, 17-23. https://doi.org/10.34194/ggub.v176.5055 _______________ The 1996 summer season saw continued petroleum geological activities in the Disko–Nuussuaq area, onshore West Greenland. These took the form of a geological field project led by the Geological Survey of Denmark and Greenland (GEUS), and continued commercial exploration by grønArctic Energy Inc. (grønArctic). In the second year of their licence, grønArctic carried out an airborne geophysical programme early in 1996 and drilled a c. 3 km deep exploration well on Nuussuaq, GRO#3, in the late summer (Fig. 1). Although the detailed results from grønArctic’s exploration are confidential (apart from the information made available at conferences and in press releases), it is evident that knowledge of the Nuussuaq Basin has greatly increased in recent years and that the basin has considerable exploration potential of its own (see Christiansen et al., 1995b, 1996a). The activities by GEUS and the exploration by grønArctic will significantly improve the understanding of the petroleum system of the basin; available data from the 1996 activities have shed light on the types and distribution of oils, source rocks and potential reservoir units.


1986 ◽  
Vol 5 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Nigel R. Ainsworth ◽  
Nicola F. Horton

Abstract. The geology, biostratigraphy and palaeoecology of exploration well Elf 55/30–1 in the Fastnet Basin are summarised. The biostratigraphical and ecological distribution of the foraminifera and Ostracoda from the late Triassic, the Lower Jurassic and the Lower Cretaceous are reviewed with reference to microfaunas elsewhere in Europe. Selected microfossil taxa are illustrated.


Author(s):  
Seyed Morteza Mirabbasi ◽  
Mohammad Javad Ameri ◽  
Mortadha Alsaba ◽  
Mohsen Karami ◽  
Amir Zargarbashi

2021 ◽  
Author(s):  
Chee Phuat Tan ◽  
Wan Nur Safawati Wan Mohd Zainudin ◽  
M Solehuddin Razak ◽  
Siti Shahara Zakaria ◽  
Thanavathy Patma Nesan ◽  
...  

Abstract Drilling in permeable formations, especially depleted reservoirs, can particularly benefit from simultaneous wellbore shielding and strengthening functionalities of drilling mud compounds. The ability to generate simultaneous wellbore shielding and strengthening in reservoirs has potential to widen stable mud weight windows to drill such reservoirs without the need to switch from wellbore strengthening compound to wellbore shielding compound, and vice-versa. Wellbore shielding and strengthening experiments were conducted on three outcrop sandstones with three mud compounds. The wellbore shielding stage was conducted by increasing the confining and borehole pressures in 4-5 steps until both reached target pressures. CT scan images demonstrate consistency of the filtration rates with observed CT scanned mud cakes which are dependent on the sandstone pore size and mud compound particle size distributions. In wellbore strengthening stage, the borehole pressure was increased until fracture was initiated, which was detected via borehole pressure trend and CT scan imaging. The fractures generated were observed to be plugged by mud filter solids which are visible in the CT scan images. The extent of observed fracture solid plugging varies with rock elastic properties, fracture width and mud compound particle size distribution. Based on the laboratory test data, fracture gradient enhancement concept was developed for the mud compounds. In addition, the data obtained and observations from the tests were used to develop optimal empirical design criteria and guidelines to achieve dual wellbore strengthening and shielding performance of the mud compounds. The design criteria were validated on a well which was treated with one of the mud compounds based on its mud loss events during drilling and running casing.


Sign in / Sign up

Export Citation Format

Share Document