Type of research: basic Duration from: 01/01/91. to 12/31/95. Papers on project (total): 75
Papers on project quoted in Current Contents: 3
Institution name: Rudarsko geološko naftni fakultet, Zagreb (195) Department/Institute: Mining, Geotechnics and Petroleum Engineering Department Petroleum Engineering Institute Address: Pierottijeva 6, 41000 Zagreb City: 10000 - Zagreb, Croatia
Communication
Phone: 385 (041) 440406
Fax: 385 (0)440008
Summary: Production of hydrocarbon fluids (oil and gas) and water
through wells is dependent on condition of inflow of such fluids through
the zone surrounding those wells. Formation damage in this zone is a
consequence of pressure of the fluid filling the well during its
drilling, completion and workover. Conditions were studied in whose
damage of the zone surrounding wells originates and how this damage can
be prevented or how consequences of it can be eliminated or decreased. By
study of relevant literature, by analysis of production parameters and by
laboratory tests which simulate in situ conditions in rocks there was an
attempt to find solutions to improve production conditions of valuable
mineral fluids. Laboratory equipment, between which own designs were too,
have been used for simulation of processes in pay zones and in wells.
From literature recepies for well killing fluids were found which do not
damage or minimally damage rocks along the wellbore. Purposeful
application of horizontal and extended-reach wells, which enable more
convenient conditions for fluid inflow into wellbore, is suggested.
Prevention of corrosion products and chemical percipitates, which can
cause formation damage, were studied too. In the years 1994 and 1995
research on influence of technology on prevention of formation damage has
been continued. Primarilly it was done by application of deviated,
extended-reach and horizontal wellbore, as well as by improvement of
borehole stability. Improved was the application of X-ray Computerized
Tomography in study of fluid flow through cores.
Keywords: formation damage, chemical formation damage, mechanical formation damage, killingof the well, horizontal well, chemical percipitate, corrosion products, mineral fluid production, X-ray Computerized Tomography
Research goals: Fundamental goal of research of the influence of
borehole fluids (drilling fluid, salt water and other fluids in wellbores)
on formation damage reduction of productive sandstones and other oil, gas
and water bearing rocks is the improvement of the quality of operations in
drilling, in well casing landing and cementing practice, in completion and
workover of wells as well as in production of commercially valuable fluids
with reduced costs per volume unit of those fluids. Expected results are:
1. Recepies of borehole fluids causing lower formation damage; 2. Design of
three-dimensional nozzles for drillin bits which for identical cleaning
efficiency as applied ones with circular openings require lower jet
velocity and lower pressure of circulating fluid on rocks at the hole
bottom; 3. Programming of drilling of extended-reach and horizontal wells
in selected fluid deposits in an aim to achieve conditions for more
favorable influx of valuable fluids into wellbores.
COOPERATION - PROJECTS
Name of project
: 2-01-135 Smanjenje propusnosti stijena
bušotinskim fluidima Name of institution: Rudarsko-geološko-naftni fakultet Sveucilišta City: 10000 - Zagreb, Croatia Other information about the project.