Exploitation of mature oil fields around the world has forced researchers to develop new ways to optimize reservoir performance from such reservoirs. To achieve that, drilling horizontal wells is an effective method. The effectiveness of this kind of wells is to increase oil withdrawal. The objective of this study is to optimize the location, design, and completion of a new horizontal well as an oil producer to improve oil recovery in a real field located in Iraq. “A” is an oil and gas condensate field located in the Northeast of Iraq. From field production history, it is realized the difficulty to control gas and water production in this kind of complex carbonate reservoir with vertical producer wells. In this study, a horizontal well design with multi-stage completion is studied and proposed to find optimal oil recovery in the southeast region of the selected field. A bulk oil well sector model is used to simulate the fluid flow of a single-porosity/single-permeability model. Then, a sensitivity analysis has been run to optimize; the well trajectory path, different scenarios on well oil and water production potential, and well completion design. The result of the well sector simulation indicates that the well trajectory with an Azimuth of 89 degrees and with a multi-stage completion design has better production performance under water production constraints. Optimum oil production rates of 1000 to 2000 STB/day, as delaying and controlling early gas and water production challenges is achieved.