Most of the world’s natural gas hydrates are found in deep-sea formations and represent a new type of clean energy with great resource potential. Unlike traditional oil and gas deposits, natural gas hydrates exist simultaneously in solid, liquid, and gas states, making their exploitation and seepage mechanisms more complex. China’s hydrates in the Shenhu area, located in the South China Sea, have a complex geological structure consisting of hydrate layers, three-phase mixed layers, and gas–water two-phase layers. These formations have low permeability and low hydrate saturation, posing challenges for well types. However, China’s second test production using horizontal wells was a resounding success, resulting in a production rate 5.57 times higher than that of the vertical well test. This marked a significant advancement in hydrate production and demonstrated the effectiveness of horizontal wells in this context. This paper establishes a three-dimensional in-homogeneous geological model of the actual hydrate reservoir and numerical models of vertical and horizontal wells for depressurization based on geological and dynamic data from two gas hydrate tests in the Shenhu area. The analysis focuses on the gas production characteristics of long-term production and the comparative study of the spatial evolution characteristics of the pressure, temperature, and saturation fields of the vertical and horizontal wells over ten years of depressurization production. It can be concluded that horizontal wells produce significantly more gas than vertical wells. Furthermore, with the increase in exploitation time, the pressure drops and low-temperature region of the hydrate reservoir around the wellbore of horizontal wells have a more extensive distribution range. The change in the hydrate, gas, and water saturation fields is more evident than that of vertical wells. Consequently, the development well network represented by horizontal wells will be the primary direction of hydrate production in the future.