App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="localcouchbase" type="Couchbase.Configuration.CouchbaseClientSection, Couchbase" />
  </configSections>

  <localcouchbase>
    <servers bucket="default">
      <add uri="http://localhost:8091/pools" />
    </servers>
  </localcouchbase>
</configuration>

packages.config

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="CouchbaseNetClient" version="1.2.0" targetFramework="net40" />
  <package id="Hammock" version="1.2.9" targetFramework="net40" />
  <package id="Newtonsoft.Json" version="4.5.11" targetFramework="net40" />
</packages>

Program.cs

using System;
using System.Configuration;
using Couchbase;
using Couchbase.Configuration;

namespace CouchbaseIncrementWithCASTest
{
    class Program
    {
        static void Main(string[] args)
        {
            var couchbaseClient = new CouchbaseClient((ICouchbaseClientConfiguration)ConfigurationManager.GetSection("localcouchbase"));
            var cacheKey = Guid.NewGuid().ToString();
            var casResult = couchbaseClient.GetWithCas<ulong>(cacheKey);
            var incrementResult = couchbaseClient.Increment(cacheKey, (ulong)DateTime.Now.Ticks, 0, TimeSpan.FromMinutes(1), casResult.Cas);
            Console.WriteLine(incrementResult.Result);
        }
    }
}