This book covers research on horizontal well seepage, fracture optimization, and water control. It analyzes nonlinear seepage in low permeability reservoirs and proposes methods for tight reservoirs. Shear fractures' impact on permeability and stress sensitivity is studied. Oil recovery, waterflooding, and residual oil distribution are examined. Simulations on depletion mining, waterflood, and CO2 flooding are included. Key development parameters are identified. Water-injection and fracturing factors in horizontal wells are explored. Technical and economic evaluations are developed. Production decline and water cut rise in fractured wells are modeled. A rheological automated water-control material is created, identifying selective entry and flow resistance. A selective plugging technique is developed. Well pattern optimization establishes rational patterns. Waterflood development policy and energy replenishment for low permeability reservoirs are optimized. Old well re-fracturing and gas injection adaptability are assessed, creating an adjustment strategy.