Well stimulation in the North Sea

Journal Article · Thu Nov 01 04:00:00 EST 1973 · Pet. Eng. Int.; (United States)

OSTI ID:6925044

Johnson, A K; LaFleur, K K

A survey of the well stimulation techniques applied in the past 6 yr in the gas wells of the southern North Sea basin indicates that fracturing is more effective in lower permeability wells and matrix acidizing in wells with better permeability. Wells in the indefatigable and Leman fields (Rotliegendes) required treatment only for formation damage removal, in the West Sole (Rotliegendes) field they required fracture stimulation, and in the Hewett (Bunter and Hewett sandstone) and Viking (Rotliegendes) fields they achieved optimum production without stimulation or treatment. Wells of higher permeability generally showed high formation damage following initial completion. The majority of the matrix acidizing treatments used an acid formulation of 85 vol percent of 15 percent HCl and 3 percent HF, plus 15 vol percent of isopropyl alcohol. Perforation ball sealers with a 1.1 specific gravity were distributed throughout the acid to distribute it over the entire perforated intervals. Pump rates varied from 8 to 22 rpm, depending on the thickness of the perforated interval. The effect of each treatment was then evaluated by acid response coefficient (ARC) curves. Fracture treatments were applied to 27 wells, all in the Rotliegendes formation. Selection of the fracturing fluids depended on the availability, friction-loss properties, carrying capacity, leakoff rate, and compatibility with the reservoir formation. Proppants used included sand, walnut shells, glass beads, and their combination. Results of each stimulation treatment were evaluated by considering each well's pre-frac, immediate post-frac, and recent performance.

• OSTI ID: 6925044
• Journal Information: Pet. Eng. Int.; (United States), Journal Name: Pet. Eng. Int.; (United States) Vol. 12
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
ACIDIZATION
ALCOHOLS
ATLANTIC OCEAN
COMMINUTION
ENERGY SOURCES
ENHANCED RECOVERY
FLUIDS
FOSSIL FUELS
FRACTURING
FUEL GAS
FUELS
GAS FUELS
GASES
HYDROCHLORIC ACID
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ACIDS
NATURAL GAS
NATURAL GAS WELLS
NORTH SEA
OIL WELLS
ORGANIC COMPOUNDS
PETROLEUM
PROPANOLS
PROPPING AGENTS
SEAS
SURFACE WATERS
WELL STIMULATION
WELLS