CARBONACEOUS OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2015 - IPC E21B43/27 E21B43/267 

FIELD: oil and gas industry.

SUBSTANCE: in a carbonaceous oil deposit development method that includes drilling of horizontal wells with a core sampling from the productive formation, performance of core laboratory tests, acid treatment and multiple hydraulic fracturing of the formation in these wells, according to the invention the core is sampled at different sections along the whole length of the horizontal shaft. The sampled core is subjected to the laboratory tests to determine the fracturing pressure, at that the sections are identified along the shaft where the minimum fracturing pressure P_min, MPa, and the maximum fracturing pressure P_max, MPa is required. Each section is treated by acid; at that the acid concentration for each section is set as identical. During the acid treatment each treated section of the formation is isolated temporarily by packers from the remaining part of the well. Then multiple proppant hydraulic fracturing of the formation is made under pressure that does not exceed P_max. At that at the sections, where P_max is required the acid treatment is performed in a volume of Q_max, m³/m, at the sections where P_min is required the acid treatment is performed in a volume not exceeding 10% of the maximum value. At the remaining sections the volume of the injected acid is defined proportionally to the obtained fracturing pressure in compliance with the following ratio: $${\text{Q}}_{\text{n}}=\frac{{\text{Q}}_{\text{min}}-{\text{Q}}_{\text{max}}}{{\text{P}}_{\text{min}}-{\text{P}}_{\text{max}}}\cdot {\text{(P}}_{\text{n}}-{\text{P}}_{\text{min}}\text{)}+{\text{Q}}_{\text{min}},$$ where Q_n is the specific volume per meter of the thickness, which is required for the injection to the n^th section of the formation along the horizontal shaft, m³/m, P_n is the required fracturing pressure at the n^th section of the formation along the horizontal shaft, MPa.

EFFECT: improved sweep efficiency and increased oil recovery of the oil deposit.

1 dwg