Abstract: A method includes transcoding a first block from a spatial region. The first block is associated with a first block tree pattern defining a structure of splitting a block into smaller blocks. A bit string of bits for the first block tree pattern is included in an encoded bitstream. The method determines a location of the first block in the spatial region when the first block tree pattern of the first block can be reused for a second block tree pattern of a second block. The spatial region includes blocks and the location is based on the first block being in the spatial region. Information for the second block is included in the encoded bitstream that indicates the location of the first block in the spatial region. The location allows the bit string for the first block tree pattern to be retrieved for use to decode the second block.

Abstract: A laser cleaning method and device for improving uniformity of a laser cleaning surface are provided. The laser cleaning method includes: applying a peaked-top sine wave signal to a motor; controlling a galvanometer to swing in a reciprocated manner by the motor; shaping a laser beam emitted by a laser to a linear beam by the reciprocated swing of the galvanometer; and performing laser cleaning using the shaped linear beam.

Abstract: A laser cleaning system including a laser source, an energy-transferring optical fiber, a laser cleaning head, a coreless motor, a connection lens barrel, and a mirror.

Abstract: A laser cleaning method and device for improving uniformity of a laser cleaning surface are provided. The laser cleaning method includes: applying a peaked-top sine wave signal to a motor; controlling a galvanometer to swing in a reciprocated manner by the motor; shaping a laser beam emitted by a laser to a linear beam by the reciprocated swing of the galvanometer; and performing laser cleaning using the shaped linear beam.

Abstract: A laser cleaning system including a laser source, an energy-transferring optical fiber, a laser cleaning head, a coreless motor, a connection lens barrel, and a mirror.

Abstract: A simulation device for integrated evaluation experiment for sand control wellbore plugging and plugging removal, including a wellbore system, a whole sand control well plugging system, a local sand control well plugging system and a plugging removal system. The wellbore system simulates downhole working conditions of the sand control wellbore. Perforations of the whole sand control well plugging system and sand-filled pipe of the local sand control well plugging system are applied on the casing pipe of the wellbore system. The plugging process of the sand control well system is simulated by pumping a sand-laden slurry into the wellbore system. The plugging removal process is simulated by setting the plugging removal tool of plugging removal system through an oil tube in the wellbore system. The plugging removal effect of the plugging removal tool is analyzed and evaluated according to the reliable data measured by the pressure gauge, flowmeter, etc.

Abstract: A simulation device for integrated evaluation experiment for sand control wellbore plugging and plugging removal, including a wellbore system, a whole sand control well plugging system, a local sand control well plugging system and a plugging removal system. The wellbore system simulates downhole working conditions of the sand control wellbore. Perforations of the whole sand control well plugging system and sand-filled pipe of the local sand control well plugging system are applied on the casing pipe of the wellbore system. The plugging process of the sand control well system is simulated by pumping a sand-laden slurry into the wellbore system. The plugging removal process is simulated by setting the plugging removal tool of plugging removal system through an oil tube in the wellbore system. The plugging removal effect of the plugging removal tool is analyzed and evaluated according to the reliable data measured by the pressure gauge, flowmeter, etc.